selftests/x86/amx: Add a ptrace test

selftests/x86/amx: Add a ptrace test

commit 62faca1ca10cc84e99ae7f38aa28df2bc945369b upstream.

Include a test case to validate the XTILEDATA injection to the target.

Also, it ensures the kernel's ability to copy states between different
XSAVE formats.

Refactor the memcmp() code to be usable for the state validation.

Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20230227210504.18520-3-chang.seok.bae%40intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>