msm: mdss: Enable clocks for WFD setup

The WFD setup path has few register writes. If the MDP clocks
aren't switched on, the register access might cause SMMU
faults. Turn on the clocks, before calling WFD setup.

Change-Id: Icc865178f43dc6068b6b4b201b8f9eada2570598
Signed-off-by: Krishna Chaitanya Devarakonda <kdevarak@codeaurora.org>