msm: display: panel frame rate report

Add metadata ioctl for retrieving panel frame rate.
Get ready to remove reserved fields usage.

Signed-off-by: Ken Zhang <kenz@codeaurora.org>

Conflicts:

	include/linux/msm_mdp.h

Change-Id: I51a4aed9d85efd5f83a184100b6a3dc682c7a67c
msm_fb: display: fix frame rate wrong calculation

For cmd mode the frame rate calculation result is wrong. Also in mdp
driver there are several places to do the same calculation. So fix the
wrong calculation and use a single func to do calculation.

(cherry picked from commit d0bf99c8cbbbb43ad5bb1c426efc7d8004f6bf6f)

Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>

Conflicts:

	drivers/video/msm/mdp.h

Change-Id: I3a4be39e480ce82677dcefb666202947f7f6d3c1