msm: mdss: compile mdss drivers with arm 64-bit toolchain

Fix mdss drivers to compile with arm 64-bit tool chain
by addressing incorrect typecasts and include appropriate
headers.

Change-Id: I342571a3cb3c801b382a36007b29a63c85e31be1
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>