mfd: Avoid to allocate 88pm860x static platform data

Maybe multiple PMIC devices are installed into one board. Static variable
can only make driver logic mess. So remove these variable, and use
platform data from platform driver instead.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>