msm: mdss: initialize shadow clocks regardless DFPS modes

Since DFPS mode can be dynamically configured through device node,
shadow clocks used by DFPS clk mode need to be initialized during boot
time regardless the default DFPS mode specified in device tree.

Change-Id: I580a05ed62a2207666ea6569abbdf588a4f8d39d
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>
Signed-off-by: Vishnuvardhan Prodduturi <vproddut@codeaurora.org>