drm/msm-hyp: overwrite hyp ioctls used by libgbm

Handle ioctls called by libgbm in the virtual kernel driver
to support front-end library and avoid modifying libgbm.

Change-Id: Ie4e567cea7338b4ba68080decf85dfa45e040dac
Signed-off-by: Camus Wong <camusw@codeaurora.org>