arm64/cpufeature: Replace custom macros with fields from ID_AA64PFR0_EL1

This replaces custom macros usage (i.e ID_AA64PFR0_EL1_ELx_64BIT_ONLY and
ID_AA64PFR0_EL1_ELx_32BIT_64BIT) and instead directly uses register fields
from ID_AA64PFR0_EL1 sysreg definition. Finally let's drop off both these
custom macros as they are now redundant.

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20240613102710.3295108-3-anshuman.khandual@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>