v4l2-common: warning fix (W=1): add a missed function prototype

changeset d1e9b7c12 added a new ancilliary function to API, but forgot
to add it to the corresponding header file.

drivers/media/v4l2-core/v4l2-ctrls.c:568:18: warning: no previous prototype for 'v4l2_ctrl_get_int_menu' [-Wmissing-prototypes]
 const s64 const *v4l2_ctrl_get_int_menu(u32 id, u32 *len)

Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

include/media/v4l2-common.h

@@ -86,6 +86,7 @@ int v4l2_ctrl_check(struct v4l2_ext_control *ctrl, struct v4l2_queryctrl *qctrl,
 		const char * const *menu_items);
 const char *v4l2_ctrl_get_name(u32 id);
 const char * const *v4l2_ctrl_get_menu(u32 id);
+const s64 const *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
 int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 min, s32 max, s32 step, s32 def);
 int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu,
 		struct v4l2_queryctrl *qctrl, const char * const *menu_items);