msm: sde: remove mdss axi clock for version 5 hw

sde rotator does not need to vote on the mdss axi clock for mdss hw
version 5. Make changes to check for hw version before accessing
the mdss axi clock.

Change-Id: I3135714802c8ee4df816e2342b702ec57fd8b1f7
Signed-off-by: Benjamin Chan <bkchan@codeaurora.org>