msm: mdss: fix calls to usleep_range function in mdss driver

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

Change-Id: I1db734fa43db399e3a7b61a08af3477d258d080f
Signed-off-by: Vishnuvardhan Prodduturi <vproddut@codeaurora.org>