msm: clock-8092: Allow setrate on mdp clock

Allow setrate to go through this mdp branch clock for mdss by disabling
the sibling. And also add entries for venus core clocks to measure
rate.

Change-Id: I158575fa512f4c6a9f63eff2aa01e044a8d79fcc
Signed-off-by: Hanumath Prasad <hpprasad@codeaurora.org>