mfd: driver for the TMIO NAND controller

This patch adds support for the NAND controller commonly found in
TMIO based MFDs.

Signed-off-by: Ian Molton <spyro@f2s.com>
Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>