msm_fb: Avoid memset of frame buffer during early suspend

At present, we have backlight disabled before frame buffer
early suspend and there is mechanism in place to enable backlight
only after first frame update after display resume. This makes sure
to avoid panel specific artifacts being visible. Hence,
remove memset of frame buffer during suspend. This change
reduces latencies during frame buffer's early suspend.

Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>
(cherry picked from commit 96ebb53ba08a96c03c89349bc1110175b85cb8be)

Change-Id: I037552e6cb01e33f738b5f3062550d8c6f9f2e6b
Signed-off-by: Gopal Goberu <ggober@codeaurora.org>

Conflicts:

	drivers/video/msm/msm_fb.c