MAINTAINERS/ACCEL: Add include/drm/drm_accel.h to the accel entry

get_maintainer.pl does not suggest Oded Gabbay, the DRM COMPUTE
ACCELERATORS DRIVERS AND FRAMEWORK maintainer for changes that touch
the Accel Subsystem header - drm_accel.h.  This is because that file is
missing from the Accel Subsystem entry.  Fix this.
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

MAINTAINERS

@@ -6893,6 +6893,7 @@ C:	irc://irc.oftc.net/dri-devel
 T:	git https://git.kernel.org/pub/scm/linux/kernel/git/ogabbay/accel.git
 F:	Documentation/accel/
 F:	drivers/accel/
+F:	include/drm/drm_accel.h
 
 DRM ACCEL DRIVERS FOR INTEL VPU
 M:	Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>