mdss: display: add mdp core clock to edp control

Since mdss interrupts are generated in mdp core clock domain,
mdp clock need to be enabled along with edp clocks to have edp
interrupt be delivered to edp during edp probe.

Change-Id: Idad19dddfdc2aed9efda15b28b666ac0411dbbda
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
msm: mdss: initialize write back arguments in kickoff

The kickoff code relies on the fact that write back arguments are zero
initialized to check for available buffer. If it's not zero initialized
it may pick dirty buffer address from stack.

Change-Id: I7309f8fe508640833a182a8ecdb2d3be1797fab7
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>