msm/sde/rotator: Initialise rotator module after MDP module init

Doing late initialization of rotator module since it depends
upon providers which are initialized during msm bind time.
Hence, calling rotator module init only after msm module
init is complete.

Change-Id: I15ea08251c639cf121e9bed1d7bd579ade78cd12
Signed-off-by: Shubhashree Dhar <dhar@codeaurora.org>