Add a testcase to check that user address with valid/invalid
mte tag works in kernel mode. This test verifies the kernel API's
__arch_copy_from_user/__arch_copy_to_user works by considering
if the user pointer has valid/invalid allocation tags.

In MTE sync mode a SIGSEV fault is generated if a user memory
with invalid tag is accessed in kernel. In async mode no such
fault occurs.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>