package/cog: mark for installation to the staging tree

The cog package includes libraries and headers, so installing it
to the staging tree allows having those available for development.

Signed-off-by: Adrian Perez de Castro <aperez@igalia.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/cog/cog.mk

@@ -6,6 +6,7 @@
 
 COG_VERSION = v0.2.0
 COG_SITE = $(call github,Igalia,cog,$(COG_VERSION))
+COG_INSTALL_STAGING = YES
 COG_DEPENDENCIES = dbus wpewebkit wpebackend-fdo
 COG_LICENSE = MIT
 COG_LICENSE_FILES = COPYING