package/freeswitch: rework OpenCV4 dependencies

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/commit/962081259d91fea1e9a59c1af85d9a85ba45d0dd

Fixes Kconfig warnings:

    WARNING: unmet direct dependencies detected for BR2_PACKAGE_OPENCV4_LIB_OBJDETECT
      Depends on [n]: BR2_PACKAGE_OPENCV4 [=y] && !BR2_TOOLCHAIN_USES_UCLIBC [=n] && BR2_PACKAGE_PROTOBUF_ARCH_SUPPORTS [=n] && BR2_TOOLCHAIN_GCC_AT_LEAST_8 [=y]
      Selected by [y]:
      - BR2_PACKAGE_FREESWITCH [=y] && BR2_INSTALL_LIBSTDCPP [=y] && !BR2_STATIC_LIBS [=n] && BR2_TOOLCHAIN_HAS_THREADS [=y] && BR2_USE_MMU [=y] && BR2_USE_WCHAR [=y] && BR2_PACKAGE_OPENCV4 [=y]

Reported-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/freeswitch/Config.in

@@ -14,9 +14,6 @@ config BR2_PACKAGE_FREESWITCH
 	select BR2_PACKAGE_OPENCV3_LIB_HIGHGUI if BR2_PACKAGE_OPENCV3
 	select BR2_PACKAGE_OPENCV3_LIB_IMGPROC if BR2_PACKAGE_OPENCV3
 	select BR2_PACKAGE_OPENCV3_LIB_OBJDETECT if BR2_PACKAGE_OPENCV3
-	select BR2_PACKAGE_OPENCV4_LIB_HIGHGUI if BR2_PACKAGE_OPENCV4
-	select BR2_PACKAGE_OPENCV4_LIB_IMGPROC if BR2_PACKAGE_OPENCV4
-	select BR2_PACKAGE_OPENCV4_LIB_OBJDETECT if BR2_PACKAGE_OPENCV4
 	select BR2_PACKAGE_OPENSSL
 	select BR2_PACKAGE_PCRE
 	select BR2_PACKAGE_SOFIA_SIP

package/freeswitch/freeswitch.mk

@@ -283,7 +283,7 @@ FREESWITCH_DEPENDENCIES += opencv3
 FREESWITCH_ENABLED_MODULES += applications/mod_cv
 endif
 
-ifeq ($(BR2_PACKAGE_OPENCV4),y)
+ifeq ($(BR2_PACKAGE_OPENCV4_LIB_HIGHGUI)$(BR2_PACKAGE_OPENCV4_LIB_IMGPROC)$(BR2_PACKAGE_OPENCV4_LIB_OBJDETECT),yyy)
 FREESWITCH_DEPENDENCIES += opencv4
 FREESWITCH_ENABLED_MODULES += applications/mod_cv
 endif