msm: mdss: share fb memory ion fd to userspace

Add new operation request to share ion fd to userspace
for mapping to the frame buffer memory.

Change-Id: I404c73c19e3fffec593ffd32c34e7b1a74a500d8
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>
Merge pull request #5 from CyanogenMod/cm-11.0

msm: mdss: share fb memory ion fd to userspace