mfd: rtsx: Support RTS5249

RTS5249 supports SD UHS-II interface.

In order to support SD UHS-II，the definitions of some internal
registers of RTS5249 have to be modified and are different from its
predecessors. So we need this patch to ensure RTS5249 can work, even
SD/MMC stack doesn't support UHS-II interface.

Signed-off-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>