msm-fb: display: Reducing the display wake up time

100 msec sleep in phy init delays system wake up. Using usleep instead of
msleep to optimize it.

Change-Id: Ibdbb771145210c9462aa68543024be2ae797be4f
Signed-off-by: Siddhartha Agrawal <agrawals@codeaurora.org>
3 files changed