kselftest/arm64: Add 2024 dpISA extensions to hwcap test

Add coverage of the hwcaps for the 2024 dpISA extensions to the hwcap
test.

We don't actually test SIGILL generation for CMPBR since the need to
branch makes it a pain to generate and the SIGILL detection would be
unreliable anyway. Since this should be very unusual we provide a stub
function rather than supporting a missing test.

The sigill functions aren't well sorted in the file so the ordering is a
bit random.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250107-arm64-2024-dpisa-v5-5-7578da51fc3d@kernel.org


Signed-off-by: Will Deacon <will@kernel.org>