dt-bindings: mfd: twl: Convert trivial subdevices to json-schema

Convert subdevices with just an interrupt and compatbile to
json-schema and wire up already converted subdevices.
RTC is available in all variants, so allow it unconditionally.
GPADC binding for TWL603X uses two different compatibles, so
specify just the compatible and do not include it.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240401081831.456828-1-andreas@kemnade.info


Signed-off-by: Lee Jones <lee@kernel.org>