package/rpcbind: add systemd as a build-time dependency

When systemd support is enabled, systemd should be built before,
otherwise the build fails with:

checking for SYSTEMD... no
configure: error: libsystemd support requested but found
package/pkg-generic.mk:228: recipe for target

Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/rpcbind/rpcbind.mk

@@ -17,6 +17,7 @@ RPCBIND_CONF_OPTS += --with-rpcuser=root
 
 ifeq ($(BR2_INIT_SYSTEMD),y)
 RPCBIND_CONF_OPTS += --with-systemdsystemunitdir=/usr/lib/systemd/system
+RPCBIND_DEPENDENCIES += systemd
 else
 RPCBIND_CONF_OPTS += --with-systemdsystemunitdir=no
 endif