mfd: 88pm860x: Use REG resource in regulator

Since IORESOURCE_IO is changed to IORESOURCE_REG in 88pm860x driver,
update self-defined IORESOURCE_IO resource to register offset that
is IORESOURCE_REG in regulator driver. And split regulator platform
data array into scattered platform data.

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