drm/msm/sde: update register writes to use SDE logging macros

Update low level register write function to use common SDE
debug macros to allow the logs to be enabled both from the
drm_debug and dynamic debug interfaces.

Change-Id: I232fcd205c52ce91f215fa0b4f2c363103c3864d
Signed-off-by: Clarence Ip <cip@codeaurora.org>