msm: mdss: move MDSS revision macros to uapi/linux/msm_mdp.h

Currently kernel driver and user mode libraries keep their own
copies of HW revision numbers. This strategy is prone to errors
and usually frowned upon. Fix this by moving revision information
to sanitized header which is shared by kernel drivers and user mode
libraries.

Change-Id: I59d1256ffd98e07f4ef9ae2b534f04b67abd2119
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>