drm/msm: align HDMI register address space mapping with SDE

HDMI driver currently maps register addresses using ioremap()
but doesn't use the SDE driver utilities for register read/write.
Copy the mapped register spaces to SDE utility headers so that
other SDE APIs can be used seamlessly for HDMI.

Change-Id: I3cbe57778ff3a63ffd9176f1a2c60778238e3fe2
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>