msm: mdss: dp: set crypto clock rate

Crypto clock is needed for HDCP 1.x/2.x encryption. If not set,
it may result in link integrity failure as source and sink may
go out of synchronization. Set the crypto clock rate as per
hardware recommendations.

Change-Id: I768b3390fbe4728be285424d0ce27981e1a5d6cb
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>