mfd: pcf50633: Remove remaining PCF50633 support

mfd: pcf50633: Remove remaining PCF50633 support

Remove the remaining parts of the 50633, the core, headers and glue.

The pcf50633 was used as part of the OpenMoko devices but
the support for its main chip was recently removed in:
commit 61b7f8920b17 ("ARM: s3c: remove all s3c24xx support")

See https://lore.kernel.org/all/Z8z236h4B5A6Ki3D@gallifrey/

Remove it.

Signed-off-by: "Dr. David Alan Gilbert" <linux@treblig.org>
Link: https://lore.kernel.org/r/20250311014959.743322-10-linux@treblig.org
Signed-off-by: Lee Jones <lee@kernel.org>