ARMClang: Fix computation of compiler semantic version patch level

According to ARMClang documentation 6.20, the patch version number
should not include the last two digits of `__ARMCOMPILER_VERSION`,
which are reserved for internal use by ARM.

Modules/Compiler/ARMClang-DetermineCompiler.cmake

@@ -4,7 +4,7 @@ set(_compiler_id_pp_test "defined(__clang__) && defined(__ARMCOMPILER_VERSION)")
 set(_compiler_id_version_compute "
   # define @PREFIX@COMPILER_VERSION_MAJOR @MACRO_DEC@(__ARMCOMPILER_VERSION/1000000)
   # define @PREFIX@COMPILER_VERSION_MINOR @MACRO_DEC@(__ARMCOMPILER_VERSION/10000 % 100)
-  # define @PREFIX@COMPILER_VERSION_PATCH @MACRO_DEC@(__ARMCOMPILER_VERSION     % 10000)")
+  # define @PREFIX@COMPILER_VERSION_PATCH @MACRO_DEC@(__ARMCOMPILER_VERSION/100   % 100)")
 
 string(APPEND _compiler_id_version_compute "
 # define @PREFIX@COMPILER_VERSION_INTERNAL @MACRO_DEC@(__ARMCOMPILER_VERSION)")