msm_fb: display: restore previous mdp bandwidth when resume

mdp resume bandwidth is set to the value when device was suspend, so
that the correct init value is set to avoid underrun.

CRs-fixed: 425823
Change-Id: Ie9b832f0eb5b5e1b6cb5e8979626986d896d340b
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>