msm: mdss: fix SMMU attach issue when using gpu composition

When gpu composition is used as default composition type.
SMMU is not attached by the time OVERLAY_PLAY ioctl get called.
This results in incorrect mapping of the buffer and causes failure
for subsequent OVERLAY_PLAY request for the same buffer.

Fix the issue by calling SMMU attach before mapping buffer in SMMU
page table via OVERLAY_PLAY ioctl.

Change-Id: Ia09b95d911aef86d0689ddb4cf7b8057d5c4f15a
Signed-off-by: Sachin Bhayare <sachin.bhayare@codeaurora.org>