tree: Rename the header and defines

The sunxi_cedrus.h header contains a bunch of defines prefixed with
SUNXI_CEDRUS.

As part as the ongoing migration to a more generic name, change that prefix
for V4L2_REQUEST, and the header file to request.h

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

src/subpicture.c

@@ -23,8 +23,8 @@
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include "request.h"
 #include "subpicture.h"
-#include "sunxi_cedrus.h"
 
 VAStatus RequestCreateSubpicture(VADriverContextP context, VAImageID image_id,
 				 VASubpictureID *subpicture_id)