change to use SConscript to enable clear bss in startup.s

bsp/imxrt/libraries/MIMXRT1050/MIMXRT1052/gcc/startup_MIMXRT1052.S

@@ -367,6 +367,7 @@ Reset_Handler:
     blt    .LC4
 #endif /* __STARTUP_INITIALIZE_NONCACHEDATA */
 
+#ifdef __STARTUP_CLEAR_BSS
 /*     This part of work usually is done in C library startup code. Otherwise,
  *     define this macro to enable it in this startup.
  *
@@ -384,6 +385,7 @@ Reset_Handler:
     itt    lt
     strlt   r0, [r1], #4
     blt    .LC5
+#endif /* __STARTUP_CLEAR_BSS */
 
     cpsie   i               /* Unmask interrupts */
 #ifndef __START

bsp/imxrt/libraries/MIMXRT1050/SConscript

@@ -76,6 +76,9 @@ if GetDepend(['BSP_USING_DMA']):
     src += ['MIMXRT1052/drivers/fsl_lpspi_edma.c']
     
 
-group = DefineGroup('Libraries', src, depend = [''], CPPPATH = path)
+if rtconfig.CROSS_TOOL == 'gcc':
+    group = DefineGroup('Libraries', src, depend = [''], CPPPATH = path, ASFLAGS = '$ASFLAGS -D __STARTUP_CLEAR_BSS')
+else:
+    group = DefineGroup('Libraries', src, depend = [''], CPPPATH = path)
 
 Return('group')

bsp/imxrt/libraries/MIMXRT1064/MIMXRT1064/gcc/startup_MIMXRT1064.S

@@ -366,6 +366,7 @@ Reset_Handler:
     blt    .LC4
 #endif /* __STARTUP_INITIALIZE_NONCACHEDATA */
 
+#ifdef __STARTUP_CLEAR_BSS
 /*     This part of work usually is done in C library startup code. Otherwise,
  *     define this macro to enable it in this startup.
  *
@@ -383,6 +384,7 @@ Reset_Handler:
     itt    lt
     strlt   r0, [r1], #4
     blt    .LC5
+#endif /* __STARTUP_CLEAR_BSS */
 
     cpsie   i               /* Unmask interrupts */
 #ifndef __START

bsp/imxrt/libraries/MIMXRT1064/SConscript

@@ -74,6 +74,9 @@ if GetDepend(['RT_SERIAL_USING_DMA']):
     src += ['MIMXRT1064/drivers/fsl_lpuart_edma.c']
     src += ['MIMXRT1064/drivers/fsl_lpspi_edma.c']
 
-group = DefineGroup('Libraries', src, depend = [''], CPPPATH = path)
+if rtconfig.CROSS_TOOL == 'gcc':
+    group = DefineGroup('Libraries', src, depend = [''], CPPPATH = path, ASFLAGS = '$ASFLAGS -D __STARTUP_CLEAR_BSS')
+else:
+    group = DefineGroup('Libraries', src, depend = [''], CPPPATH = path)
 
 Return('group')