mfd: Append additional read write on 88pm860x

Append the additional read/write operation on 88pm860x for accessing
test page in 88PM860x.

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