package/gnuradio: add optional log4cpp dependency

Currently, logger component is enabled if log4cpp is found

Moreover, it should be noted that log4cpp is now mandatory in latest
upstream:
https://github.com/gnuradio/gnuradio/commit/d2428961205bf62e6b39966f040f98435e5cc2ed

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/gnuradio/Config.in

@@ -56,6 +56,12 @@ config BR2_PACKAGE_GNURADIO_FEC
 	help
 	  FEC signal processing blocks
 
+config BR2_PACKAGE_GNURADIO_LOG
+	bool "gr-log support"
+	select BR2_PACKAGE_LOG4CPP
+	help
+	  Enable logger component
+
 config BR2_PACKAGE_GNURADIO_PYTHON
 	bool "python support"
 	depends on BR2_PACKAGE_PYTHON

package/gnuradio/gnuradio.mk

@@ -115,6 +115,13 @@ else
 GNURADIO_CONF_OPTS += -DENABLE_GR_FILTER=OFF
 endif
 
+ifeq ($(BR2_PACKAGE_GNURADIO_LOG),y)
+GNURADIO_DEPENDENCIES += log4cpp
+GNURADIO_CONF_OPTS += -DENABLE_GR_LOG=ON
+else
+GNURADIO_CONF_OPTS += -DENABLE_GR_LOG=OFF
+endif
+
 ifeq ($(BR2_PACKAGE_GNURADIO_PYTHON),y)
 GNURADIO_DEPENDENCIES += python
 GNURADIO_CONF_OPTS += -DENABLE_PYTHON=ON