* [MKISOFS] Fix Clang check for macOS platforms
On macOS, CMAKE_C_COMPILER_ID is "AppleClang". While certainly Clang,
this does not match the exact string "Clang" that is being checked for,
and as a result the warning flags guarded thereby are not passed to the
compiler. With this change CMake will recognize both Clang and AppleClang.
* Update sdk/tools/mkisofs/CMakeLists.txt