dt-bindings: arm/cpus: Add schemas for "enable-method" dependencies

dt-bindings: arm/cpus: Add schemas for "enable-method" dependencies

Replace the prose for properties dependent on specific "enable-method"
values with schemas defining the same requirements.

Both "qcom,acc" and "qcom,saw" properties appear to be required for any
of the Qualcomm enable-method values, so the schema is a bit simpler
than what the text said. The properties are also needed on some Qualcomm
platforms with other enable-method values. It's limited to Cortex A53
based platforms so use that to disable the properties. The references
to arm/msm/qcom,saw2.txt and arm/msm/qcom,kpss-acc.txt are out of date,
so just drop them.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20250410-dt-cpu-schema-v2-12-63d7dc9ddd0a@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>