Currectly just standard header path can be found,
check_type/struct will fail if vaapi is installed somewhere else.

Move them followed "check_pkg_config"
Reviewed-by: Mark Thompson <sw@jkqxz.net>
Reviewed-by: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: Zhong Li <zhong.li@intel.com>