drm/msm: add edid parser api

This change adds edid parser api. This api is useful in cases
where sde_edid clients already has edid and only needs parsing.

Change-Id: Ide9a81edbc6b028133c58acd7d839e6fa6355ad2
Signed-off-by: Govinda Rajulu Chenna <gchenna@codeaurora.org>