media: mtk-mdp: constify v4l2_m2m_ops structures

The v4l2_m2m_ops structures are only passed as the only
argument to v4l2_m2m_init, which is declared as const.
Thus the v4l2_m2m_ops structures themselves can be const.

Done with the help of Coccinelle.

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct v4l2_m2m_ops i@p = { ... };

@ok1@
identifier r.i;
position p;
@@
v4l2_m2m_init(&i@p)

@bad@
position p != {r.p,ok1.p};
identifier r.i;
struct v4l2_m2m_ops e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct v4l2_m2m_ops i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c

···
 	.mmap		= v4l2_m2m_fop_mmap,
 };
 
-static struct v4l2_m2m_ops mtk_mdp_m2m_ops = {
+static const struct v4l2_m2m_ops mtk_mdp_m2m_ops = {
 	.device_run	= mtk_mdp_m2m_device_run,
 	.job_abort	= mtk_mdp_m2m_job_abort,
 };