msm: Allocate fd with O_CLOEXEC flag

(cherry-pick from 'commit 580ec70a ("fbdev: msm: Allocate fd
 with O_CLOEXEC flag")') and made similar changes
for MDP3.

When fd is requested during get_metadata call, create
fd using O_CLOEXEC flag.

Change-Id: Iaa55927ac04b019ea45fbdfe9c64b10d1f0e3ceb
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>