psb_video: make it work with libva 1.3.0

All the functionality that is not yet merged to libva master
branch is compiled out as it is not used on Chromium OS

Entry points are dyamically obtained by the libva application
the driver should not use EntrypointMax as a reference. To
allocate memory a value is provided to accomodate all entrypoints
possible.

Signed-off-by: Daniel Charles <daniel.charles@intel.com>