kselftest/arm64: add test item that support to capturing the SIGBUS signal

Some enhanced features, such as the LSE2 feature, do not result in
SILLILL if LSE2 is missing and LSE is present, but will generate a
SIGBUS exception when atomic access unaligned.

Therefore, we add test item to test this type of features.

Notice that testing for SIGBUS only makes sense after make sure that
the instruction does not cause a SIGILL signal.

Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230808134036.668954-5-zengheng4@huawei.com


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