clk: mdss: implement new pll locking sequence

The new sequence is intended to improve pll locking time. This patch
is part of new sequence in pll driver side.

Change-Id: I09760d52db12deda0c0b4bf700db301cde8a05f1
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>
Signed-off-by: Ian Maund <imaund@codeaurora.org>
[narendram@codeaurora.org: Resolved context conflicts]
Signed-off-by: Narendra Muppalla <narendram@codeaurora.org>