jack2: add staging installation

jack2 installs some headers and libraries that can be used by other
applications, so it makes sense to install it to the staging
directory.

Signed-off-by: Pieter De Gendt <pieter.degendt@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/jack2/jack2.mk

@@ -8,6 +8,7 @@ JACK2_VERSION = ab409a65df95bc261ff72b52d6b3f4a65cf3266a
 JACK2_SITE = $(call github,jackaudio,jack2,$(JACK2_VERSION))
 JACK2_LICENSE = GPLv2+ (jack server), LGPLv2.1+ (jack library)
 JACK2_DEPENDENCIES = libsamplerate libsndfile alsa-lib host-python
+JACK2_INSTALL_STAGING = YES
 
 define JACK2_CONFIGURE_CMDS
 	(cd $(@D); \
@@ -27,4 +28,9 @@ define JACK2_INSTALL_TARGET_CMDS
 		install)
 endef
 
+define JACK2_INSTALL_STAGING_CMDS
+	(cd $(@D); $(HOST_DIR)/usr/bin/python2 ./waf --destdir=$(STAGING_DIR) \
+		install)
+endef
+
 $(eval $(generic-package))