drm: msm: dp: remove crypto clock parsing and rate setting

Remove crypto clock parsing and rate setting logic from the
mainlink clock enable path as the crypto clock is only required
when HDCP is enabled.

CRs-Fixed: 2020938
Change-Id: If379e158a7da099a34d34701e6bce12a1ff1a291
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>