rtos: fix incorrect conflict resolution

We used previously __FPU_USED so stay with it in M33 startup file.

Author: 0xc0170

rtos/source/TARGET_CORTEX/rtx5/RTX/Source/TOOLCHAIN_ARM/TARGET_M33/irq_armv8mml.S

@@ -89,7 +89,7 @@ SVC_Context
                 IT       EQ
                 BXEQ     LR                     ; Exit when threads are the same
 
-                IF       FPU_USED = 1
+                IF       __FPU_USED = 1
                 CBNZ     R1,SVC_ContextSave     ; Branch if running thread is not deleted
                 TST      LR,#0x10               ; Check if extended stack frame
                 BNE      SVC_ContextSwitch
@@ -114,7 +114,7 @@ SVC_ContextSave
 SVC_ContextSave1
                 MRS      R0,PSP                 ; Get PSP
                 STMDB    R0!,{R4-R11}           ; Save R4..R11
-                IF       FPU_USED = 1
+                IF       __FPU_USED = 1
                 TST      LR,#0x10               ; Check if extended stack frame
                 IT       EQ
                 VSTMDBEQ R0!,{S16-S31}          ;  Save VFP S16.S31
@@ -155,7 +155,7 @@ SVC_ContextRestore1
                 BNE      SVC_ContextRestore2    ; Branch if secure
                 ENDIF
 
-                IF       FPU_USED = 1
+                IF       __FPU_USED = 1
                 TST      LR,#0x10               ; Check if extended stack frame
                 IT       EQ
                 VLDMIAEQ R0!,{S16-S31}          ;  Restore VFP S16..S31
@@ -248,7 +248,7 @@ Sys_ContextSave1
 Sys_ContextSave2
                 MRS      R0,PSP                 ; Get PSP
                 STMDB    R0!,{R4-R11}           ; Save R4..R11
-                IF       FPU_USED = 1
+                IF       __FPU_USED = 1
                 TST      LR,#0x10               ; Check if extended stack frame
                 IT       EQ
                 VSTMDBEQ R0!,{S16-S31}          ;  Save VFP S16.S31
@@ -289,7 +289,7 @@ Sys_ContextRestore1
                 BNE      Sys_ContextRestore2    ; Branch if secure
                 ENDIF
 
-                IF       FPU_USED = 1
+                IF       __FPU_USED = 1
                 TST      LR,#0x10               ; Check if extended stack frame
                 IT       EQ
                 VLDMIAEQ R0!,{S16-S31}          ;  Restore VFP S16..S31