drm/i915: Bump command parser version number.

This was forgotten in

commit d351f6d948
Author: Francisco Jerez <currojerez@riseup.net>
Date:   Fri May 29 16:44:15 2015 +0300

    drm/i915: Add SCRATCH1 and ROW_CHICKEN3 to the register whitelist.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_cmd_parser.c

@@ -1213,6 +1213,7 @@ int i915_cmd_parser_get_version(void)
 	 * 2. Allow access to the MI_PREDICATE_SRC0 and
 	 *    MI_PREDICATE_SRC1 registers.
 	 * 3. Allow access to the GPGPU_THREADS_DISPATCHED register.
+	 * 4. L3 atomic chicken bits of HSW_SCRATCH1 and HSW_ROW_CHICKEN3.
 	 */
-	return 3;
+	return 4;
 }