package/libungif: deprecate package

To be replaced with giflib.

Follow-up of http://patchwork.ozlabs.org/patch/432990/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libungif/Config.in

@@ -1,5 +1,7 @@
 config BR2_PACKAGE_LIBUNGIF
 	bool "libungif"
+	depends on !BR2_PACKAGE_GIFLIB
+	depends on BR2_DEPRECATED_SINCE_2015_02 # giflib
 	help
 	  libungif is a library for handling the uncompressed GIF image format.