mfd: rtsx: Fix PM suspend for 5227 & 5249

Fix rts5227&5249 failed send buffer cmd after suspend,
PM_CTRL3 should reset before send any buffer cmd after suspend.
Otherwise, buffer cmd will failed, this will lead resume fail.

Signed-off-by: Micky Ching <micky_ching@realsil.com.cn>
Signed-off-by: Lee Jones <lee.jones@linaro.org>