msm: mdss: Check ctl power on status before BTA status check

Control path power on status should be checked before BTA status
check else command sending failure and IOMMU page faults during
bootup can be observed if ESD is enabled for device. Currently
IOMMU is not powered on when commands are being sent.

Change-Id: Ice66f38e79755eb14843fc63afe058e4bab2f0e2
Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>