pakcage.mosquitto: add option to install CLI tools

mosquitto_pub/sub/rr can be handy to test a broker from the command
line, but they can get superfluous when only the broker is required
on the target.

Add an option to enable or disable them. Make that new option enabled
by default to keep backward compatibility with previous (def)config
files.

Signed-off-by: Yann E. MORIN <yann.morin@orange.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Titouan Christophe <titouan.christophe@mind.be>
Signed-off-by: Romain Naour <romain.naour@smile.fr>

package/mosquitto/Config.in

@@ -24,6 +24,15 @@ config BR2_PACKAGE_MOSQUITTO
 
 if BR2_PACKAGE_MOSQUITTO
 
+config BR2_PACKAGE_MOSQUITTO_CLIENTS
+	bool "install clients"
+	default y  # Backward compatibility
+	help
+	  Install CLI tools to publish/subscribe to the broker:
+	    mosquitto_pub
+	    mosquitto_sub
+	    mosquitto_rr
+
 config BR2_PACKAGE_MOSQUITTO_BROKER
 	bool "install the mosquitto broker"
 	default y

package/mosquitto/mosquitto.mk

@@ -19,7 +19,6 @@ MOSQUITTO_CONF_OPTS = \
 	-DWITH_TESTS=OFF \
 	-DWITH_STATIC_LIBRARIES=OFF \
 	-DWITH_BUNDLED_DEPS=ON \
-	-DWITH_CLIENTS=ON \
 	-DWITH_HTTP_API=OFF \
 	-DWITH_CTRL_SHELL=OFF
 
@@ -70,6 +69,12 @@ else
 MOSQUITTO_CONF_OPTS += -DWITH_LIB_CPP=OFF
 endif
 
+ifeq ($(BR2_PACKAGE_MOSQUITTO_CLIENTS),y)
+MOSQUITTO_CONF_OPTS += -DWITH_CLIENTS=ON
+else
+MOSQUITTO_CONF_OPTS += -DWITH_CLIENTS=OFF
+endif
+
 ifeq ($(BR2_PACKAGE_MOSQUITTO_BROKER),y)
 
 MOSQUITTO_CONF_OPTS += \