arch/sim: add implemntation of 'host_sleep'.

Change-Id: Ib82343565ca9541499dec52c753c3f15923f7d1c
Signed-off-by: zhongan <zhongan@xiaomi.com>

arch/sim/src/sim/up_hosttime.c

@@ -58,6 +58,15 @@ uint64_t host_gettime(bool rtc)
   return 1000000000ull * tp.tv_sec + tp.tv_nsec;
 }
 
+/****************************************************************************
+ * Name: host_sleep
+ ****************************************************************************/
+
+void host_sleep(uint64_t nsec)
+{
+  usleep(nsec);
+}
+
 /****************************************************************************
  * Name: host_sleepuntil
  ****************************************************************************/

arch/sim/src/sim/up_internal.h

@@ -231,6 +231,7 @@ void *host_alloc_heap(size_t sz);
 /* up_hosttime.c ************************************************************/
 
 uint64_t host_gettime(bool rtc);
+void host_sleep(uint64_t nsec);
 void host_sleepuntil(uint64_t nsec);
 
 /* up_simsmp.c **************************************************************/

arch/sim/src/sim/up_rptun.c

@@ -229,7 +229,7 @@ int up_rptun_init(void)
 
       while (g_dev.shmem->base == 0)
         {
-          up_hostusleep(1000);
+          host_sleep(1000);
         }
 
       s_addrenv[0].va               = (uintptr_t)g_dev.shmem;