arm64/cpufeature: Always use symbolic name for feature value in hwcaps

Our table of hwcaps sometimes uses the defined constant to specify the
enumeration value they are attempting to match but in some cases an
unadorned number is used. In preparation for using helper macros to to
specify the hwcaps less verbosely replace the magic numbers with their
constants, this will hopefully make the conversion to helper macros
easier to review.

There should be no functional effect from this change, a check of the
generate .rodata showed no differences.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221207-arm64-sysreg-helpers-v4-4-25b6b3fb9d18@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>