[Scons][iar][iccarm] IAR统一使用iccarm作为判断条件而不是是用IDE的名字来进行判断

因为不确定后续IAR是否会像Keil一样内含有不同的编译工具链
此外，将判断条件改为列表方式，这样更方便后续增加其他可能的IAR编译链

components/libc/compilers/common/SConscript

@@ -9,7 +9,7 @@ CPPDEFINES = []
 
 if rtconfig.PLATFORM in ['armcc', 'armclang']:
     CPPDEFINES += ['__CLK_TCK=RT_TICK_PER_SECOND']
-elif rtconfig.PLATFORM == 'iar':
+elif rtconfig.PLATFORM in ['iccarm']:
     CPPDEFINES += ['CLOCKS_PER_SEC=RT_TICK_PER_SECOND'] # forcly revert to 1 by IAR
 
 src += Glob('*.c')

components/libc/compilers/dlib/SConscript

@@ -6,7 +6,7 @@ group = []
 
 CPPDEFINES = ['RT_USING_DLIBC', 'RT_USING_LIBC', '_DLIB_ADD_EXTRA_SYMBOLS=0']
 
-if rtconfig.PLATFORM == 'iar':
+if rtconfig.PLATFORM in ['iccarm']:
     if GetDepend('DFS_USING_POSIX'):
         from distutils.version import LooseVersion
         from iar import IARVersion