media: bcm2835-unicam: Reinstate V4L2_CAP_READWRITE in the caps

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

v4l2-compliance throws a failure if the device doesn't advertise
V4L2_CAP_READWRITE but allows read or write operations.
We do support read, so reinstate the flag.
Signed-off-by: NDave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/media/platform/bcm2835/bcm2835-unicam.c

@@ -2418,8 +2418,8 @@ static int register_node(struct unicam_device *unicam, struct unicam_node *node,
 	vdev->queue = q;
 	vdev->lock = &node->lock;
 	vdev->device_caps = (pad_id == IMAGE_PAD) ?
-			    (V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING) :
-			    (V4L2_CAP_META_CAPTURE | V4L2_CAP_STREAMING);
+				V4L2_CAP_VIDEO_CAPTURE : V4L2_CAP_META_CAPTURE;
+	vdev->device_caps |= V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
 
 	/* Define the device names */
 	snprintf(vdev->name, sizeof(vdev->name), "%s-%s", UNICAM_MODULE_NAME,