kselftest/arm64: Fix hwcaps selftest build

kselftest/arm64: Fix hwcaps selftest build

The hwcaps selftest currently relies on the assembler being able to
assemble the crc32w instruction but this is not in the base v8.0 so is not
accepted by the standard GCC configurations used by many distributions.
Switch to manually encoding to fix the build.

Fixes: 09d2e95a04ad ("kselftest/arm64: add crc32 feature to hwcap test")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230816-arm64-fix-crc32-build-v1-1-40165c1290f2@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>