arm64: cpufeature: fold cpus_set_cap() into update_cpu_capabilities()

arm64: cpufeature: fold cpus_set_cap() into update_cpu_capabilities()

We only use cpus_set_cap() in update_cpu_capabilities(), where we
open-code an analgous update to boot_cpucaps.

Due to the way the cpucap_ptrs[] array is initialized, we know that the
capability number cannot be greater than or equal to ARM64_NCAPS, so the
warning is superfluous.

Fold cpus_set_cap() into update_cpu_capabilities(), matching what we do
for the boot_cpucaps, and making the relationship between the two a bit
clearer.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230607164846.3967305-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>