mfd: Add PCMCIA/CF support to asic3

This patch is part of a set which adds PCMCIA/CF support for the hx4700.
This patch adds asic3_set_register() calls to:
1. Enable the PCMCIA/CF in asic3_probe().
2. Disable the PCMCIA/CF in asic3_remove().

Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Acked-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>