RTX5: fixed __get_PSP function for Cortex-A on IAR (#288)

Author: VladimirUmek

rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_core_ca.h

@@ -73,12 +73,17 @@ static __asm    uint32_t __get_PSP (void) {
   bx    lr
 }
 #else
+#ifdef __ICCARM__
+__arm
+#endif
 __STATIC_INLINE uint32_t __get_PSP (void) {
   register uint32_t ret;
 
-  __asm volatile (
+  __ASM volatile (
+#ifndef __ICCARM__
     ".syntax unified\n\t"
     ".arm\n\t"
+#endif
     "sub  sp,sp,#4\n\t"
     "stm  sp,{sp}^\n\t"
     "pop  {%[ret]}\n\t"