Revert "msm: mdss: enable mmagic gdsc before turning on mdp gdsc"

This reverts commit 3c2ffe73f03a1bfced4239b16d3284b2397f392c.
Clock change added support to handle the mmagic gdsc as
parent of core gdsc. This removes the requirement from
each mm core to vote explicitly for mmagic gdsc.

Change-Id: I10e0b3cc9bcb2bd5f4a850e1b8800b45f7305d67
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>