[media] s5p-g2d: Add missing static storage class in g2d.c file

Fixes the following sparse warnings:
drivers/media/video/s5p-g2d/g2d.c:68:18: warning: symbol 'def_frame' was not declared. Should it be static?
drivers/media/video/s5p-g2d/g2d.c:80:16: warning: symbol 'find_fmt' was not declared. Should it be static?
drivers/media/video/s5p-g2d/g2d.c:205:5: warning: symbol 'g2d_setup_ctrls' was not declared. Should it be static?

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/s5p-g2d/g2d.c

@@ -65,7 +65,7 @@ static struct g2d_fmt formats[] = {
 };
 #define NUM_FORMATS ARRAY_SIZE(formats)
 
-struct g2d_frame def_frame = {
+static struct g2d_frame def_frame = {
 	.width		= DEFAULT_WIDTH,
 	.height		= DEFAULT_HEIGHT,
 	.c_width	= DEFAULT_WIDTH,
@@ -77,7 +77,7 @@ struct g2d_frame def_frame = {
 	.bottom		= DEFAULT_HEIGHT,
 };
 
-struct g2d_fmt *find_fmt(struct v4l2_format *f)
+static struct g2d_fmt *find_fmt(struct v4l2_format *f)
 {
 	unsigned int i;
 	for (i = 0; i < NUM_FORMATS; i++) {
@@ -202,7 +202,7 @@ static const struct v4l2_ctrl_ops g2d_ctrl_ops = {
 	.s_ctrl		= g2d_s_ctrl,
 };
 
-int g2d_setup_ctrls(struct g2d_ctx *ctx)
+static int g2d_setup_ctrls(struct g2d_ctx *ctx)
 {
 	struct g2d_dev *dev = ctx->dev;