msm: mdss: Fix clocks disable sequence

When disabling the clocks that MDP depends on during an ON to OFF
transition, it is necessary to reverse the clock enabling sequence.
Otherwise, the MDSS AHB clock will stuck in a halt state and cannot
be turned off.

CRs-Fixed: 2004996
Change-Id: I0da7df14e2084701c95fd08585b9a41e0a8cb653
Signed-off-by: Benjamin Chan <bkchan@codeaurora.org>