[bsp][stm32] clean up the code

bsp/stm32/libraries/templates/stm32f4xx/board/SConscript

@@ -34,4 +34,4 @@ elif rtconfig.CROSS_TOOL == 'iar':
 CPPDEFINES = ['STM32F407xx']
 group = DefineGroup('Drivers', src, depend = [''], CPPPATH = path, CPPDEFINES = CPPDEFINES)
 
-Return('group')
+Return('group')

bsp/stm32/libraries/templates/stm32f4xx/board/linker_scripts/link.icf

@@ -25,4 +25,4 @@ do not initialize  { section .noinit };
 place at address mem:__ICFEDIT_intvec_start__ { readonly section .intvec };
 
 place in ROM_region   { readonly };
-place in RAM_region   { readwrite, last block CSTACK};
+place in RAM_region   { readwrite, last block CSTACK};

bsp/stm32/libraries/templates/stm32f7xx/rtconfig.py

@@ -132,4 +132,4 @@ elif PLATFORM == 'iar':
     LFLAGS += ' --entry __iar_program_start'
 
     EXEC_PATH = EXEC_PATH + '/arm/bin/'
-    POST_ACTION = 'ielftool --bin $TARGET rtthread.bin'
+    POST_ACTION = 'ielftool --bin $TARGET rtthread.bin'