package/mjpg-streamer: remove optional dependency to opencv3

OpenCV3 is unmaintained and will be removed from buildroot.

The package does not support OpenCV4:
https://github.com/jacksonliam/mjpg-streamer/commit/216c090707ffd71fdf86b0c5b182954846e01bd4

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/mjpg-streamer/mjpg-streamer.mk

@@ -10,6 +10,7 @@ MJPG_STREAMER_SUBDIR = mjpg-streamer-experimental
 MJPG_STREAMER_LICENSE = GPL-2.0+
 MJPG_STREAMER_LICENSE_FILES = $(MJPG_STREAMER_SUBDIR)/LICENSE
 MJPG_STREAMER_DEPENDENCIES = jpeg
+MJPG_STREAMER_CONF_OPTS = -DPLUGIN_INPUT_OPENCV=OFF
 
 ifeq ($(BR2_PACKAGE_LIBGPHOTO2),y)
 MJPG_STREAMER_CONF_OPTS += -DPLUGIN_INPUT_PTP2=ON
@@ -22,16 +23,6 @@ ifeq ($(BR2_PACKAGE_LIBV4L),y)
 MJPG_STREAMER_DEPENDENCIES += libv4l
 endif
 
-ifeq ($(BR2_PACKAGE_OPENCV3_LIB_HIGHGUI)$(BR2_PACKAGE_OPENCV3_LIB_IMGPROC)$(BR2_PACKAGE_OPENCV3_LIB_VIDEOIO),yyy)
-MJPG_STREAMER_CONF_OPTS += \
-	-DPLUGIN_INPUT_OPENCV=ON \
-	-DPLUGIN_CVFILTER_CPP=OFF \
-	-DPLUGIN_CVFILTER_PY=OFF
-MJPG_STREAMER_DEPENDENCIES += host-pkgconf opencv3
-else
-MJPG_STREAMER_CONF_OPTS += -DPLUGIN_INPUT_OPENCV=OFF
-endif
-
 ifeq ($(BR2_PACKAGE_PROTOBUF_C)$(BR2_PACKAGE_ZEROMQ),yy)
 MJPG_STREAMER_CONF_OPTS += -DPLUGIN_OUTPUT_ZMQSERVER=ON
 MJPG_STREAMER_DEPENDENCIES += host-pkgconf protobuf-c zeromq