Squashed commit of the following:
configs/makerlisp/scripts/makerlisp_ram.linkcmd: Fixup .RESET and .STARTUP. These need to be redirected to RAM since they default to ROM.
configs/makerlisp/scripts/makerlisp_ram.linkcmd: Restore some settings that should be unnecessary but are really required by the current implementation.
configs/makerlisp: Rename nsh configuratinon to nsh_flash. Create new configuration, nsh_ram, that is identical to the nsh_flash configuration except that the code runs out of external SRAM.
configs/makerlisp/scripts: Add a linker script to support execution from RAM.
nuttx/arch/z80/src: To properly follow the coding standard, the z80 architecture common should up_mmuinit should be called z80_mmu_initialize.
nuttx/arch/z80/src: To properly follow the coding standard, the z80 architecture common should up_loweserialinit should be called z80_lowserial_initialize.
configs/z80sim/src/z80_serial.c: Remove unused function up_earlyserialinit()
nuttx/arch/z80/src: To properly follow the coding standard, the z80 architecture common should up_serialinit should be called z80_serial_initialize.
nuttx/arch/z80/src: To properly follow the coding standard, the z80 architecture common should up_doirq should be called z80_doirq.
arch/z80/src/common: up_addregion() must be prototyped in nuttx/mm/mm.h, not up_internal.h
