arm64: Expose ARM64_CORE_REG() for general use Expose the macro such that it may be used to get SMCCC arguments in a future change. Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will@kernel.org>