drm/msm/sde: fix arguments of usleep_range function

usleep_range is getting called with wrong arguments which in turn
is causing the thread to go to infinite sleep. This patch fixes all
such instances in DRM display driver.

Change-Id: Icf327267fdc6104d4325be00ff9f925782fcc4bd
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>