The TC35892 I/O Expander provides 24 GPIOs, a keypad controller, timers,
and a rotator wheel interface.  This patch adds the MFD core.
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>