arm64/sysreg: Standardise naming of ID_AA64PFR1_EL1 fractional version fields

arm64/sysreg: Standardise naming of ID_AA64PFR1_EL1 fractional version fields

The naming for fractional versions fields in ID_AA64PFR1_EL1 does not align
with that in the architecture, lacking underscores and using upper case
where the architecture uses lower case. In preparation for automatic
generation of defines bring the code in sync with the architecture, no
functional change.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-18-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>