RISC-V: Remove riscv_cpuindex.c from platforms that don't need it

riscv_mhartid is no longer called by exception_common, so can remove
this file from platforms that don't need it.

Also fixes make warning:
Makefile:123: target 'riscv_cpuindex.o' given more than once in the same rule

arch/risc-v/src/bl602/Make.defs

@@ -34,7 +34,7 @@ CMN_CSRCS += riscv_releasepending.c riscv_reprioritizertr.c
 CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_udelay.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_idle.c riscv_tcbinfo.c riscv_getnewintctx.c riscv_doirq.c
-CMN_CSRCS += riscv_cpuindex.c riscv_exception.c
+CMN_CSRCS += riscv_exception.c
 
 ifeq ($(CONFIG_SCHED_BACKTRACE),y)
 CMN_CSRCS += riscv_backtrace.c

arch/risc-v/src/c906/Make.defs

@@ -34,7 +34,7 @@ CMN_CSRCS += riscv_releasepending.c riscv_reprioritizertr.c
 CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_mdelay.c riscv_idle.c riscv_doirq.c
-CMN_CSRCS += riscv_tcbinfo.c riscv_getnewintctx.c riscv_cpuindex.c
+CMN_CSRCS += riscv_tcbinfo.c riscv_getnewintctx.c
 
 ifeq ($(CONFIG_SCHED_BACKTRACE),y)
 CMN_CSRCS += riscv_backtrace.c

arch/risc-v/src/esp32c3/Make.defs

@@ -41,7 +41,6 @@ CMN_CSRCS += riscv_releasepending.c riscv_reprioritizertr.c
 CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_udelay.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_tcbinfo.c riscv_getnewintctx.c riscv_doirq.c
-CMN_CSRCS += riscv_cpuindex.c
 
 ifeq ($(CONFIG_SCHED_BACKTRACE),y)
 CMN_CSRCS += riscv_backtrace.c

arch/risc-v/src/fe310/Make.defs

@@ -34,7 +34,6 @@ CMN_CSRCS += riscv_releasepending.c riscv_reprioritizertr.c
 CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_udelay.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_idle.c riscv_tcbinfo.c riscv_getnewintctx.c riscv_doirq.c
-CMN_CSRCS += riscv_cpuindex.c
 
 ifeq ($(CONFIG_SCHED_BACKTRACE),y)
 CMN_CSRCS += riscv_backtrace.c

arch/risc-v/src/k210/Make.defs

@@ -35,7 +35,6 @@ CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_mdelay.c riscv_idle.c riscv_doirq.c
 CMN_CSRCS += riscv_tcbinfo.c riscv_cpuidlestack.c riscv_getnewintctx.c
-CMN_CSRCS += riscv_cpuindex.c
 
 ifeq ($(CONFIG_SMP), y)
 CMN_CSRCS += riscv_cpuindex.c riscv_cpupause.c riscv_cpustart.c

arch/risc-v/src/litex/Make.defs

@@ -34,7 +34,6 @@ CMN_CSRCS += riscv_releasepending.c riscv_reprioritizertr.c
 CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_udelay.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_idle.c riscv_tcbinfo.c riscv_getnewintctx.c
-CMN_CSRCS += riscv_cpuindex.c
 
 ifeq ($(CONFIG_SCHED_BACKTRACE),y)
 CMN_CSRCS += riscv_backtrace.c

arch/risc-v/src/qemu-rv/Make.defs

@@ -35,7 +35,6 @@ CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_idle.c riscv_tcbinfo.c riscv_cpuidlestack.c
 CMN_CSRCS += riscv_exception.c riscv_getnewintctx.c riscv_doirq.c
-CMN_CSRCS += riscv_cpuindex.c
 
 ifeq ($(CONFIG_SMP), y)
 CMN_CSRCS += riscv_cpuindex.c riscv_cpupause.c riscv_cpustart.c

arch/risc-v/src/rv32m1/Make.defs

@@ -34,7 +34,6 @@ CMN_CSRCS += riscv_releasepending.c riscv_reprioritizertr.c
 CMN_CSRCS += riscv_releasestack.c riscv_stackframe.c riscv_schedulesigaction.c
 CMN_CSRCS += riscv_sigdeliver.c riscv_unblocktask.c riscv_usestack.c
 CMN_CSRCS += riscv_idle.c riscv_tcbinfo.c riscv_getnewintctx.c
-CMN_CSRCS += riscv_cpuindex.c
 
 ifeq ($(CONFIG_SCHED_BACKTRACE),y)
 CMN_CSRCS += riscv_backtrace.c