media: s5p-mfc: Use real device for request_firmware() call

Provide proper (real) struct device to request_firmware() call. This fixes
following error messages:

(NULL device *): Direct firmware load for s5p-mfc-v6-v2.fw failed with error -2
(NULL device *): Direct firmware load for s5p-mfc-v6.fw failed with error -2

into a bit more meaningful ones:

s5p-mfc 11000000.codec: Direct firmware load for s5p-mfc-v6-v2.fw failed with error -2
s5p-mfc 11000000.codec: Direct firmware load for s5p-mfc-v6.fw failed with error -2
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/s5p-mfc/s5p_mfc_ctrl.c

@@ -62,7 +62,7 @@ int s5p_mfc_load_firmware(struct s5p_mfc_dev *dev)
 		if (!dev->variant->fw_name[i])
 			continue;
 		err = request_firmware((const struct firmware **)&fw_blob,
-				dev->variant->fw_name[i], dev->v4l2_dev.dev);
+				dev->variant->fw_name[i], &dev->plat_dev->dev);
 		if (!err) {
 			dev->fw_ver = (enum s5p_mfc_fw_ver) i;
 			break;