toolchain: xt-clang: skip printf format checks

For some reasons, xt-clang does not like "%hhd" or "%hd"
(for example) being fed int data (same goes for unsigned ones)
and will always complain about mismatched types. GCC and newer
LLVM/Clang do not complain. This could be due to xt-clang
being based on older LLVM/Clang. So skip the check.

Fixes: #89008

Signed-off-by: Daniel Leung <daniel.leung@intel.com>