gdb: deprecate version 7.7.x

Now that 7.9 was added and 7.8.x is default we don't want to have a
dozen versions so mark it as deprecated.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gdb/Config.in.host

@@ -33,6 +33,7 @@ choice
 
 	config BR2_GDB_VERSION_7_7
 		bool "gdb 7.7.x"
+		depends on BR2_DEPRECATED_SINCE_2015_05
 
 	config BR2_GDB_VERSION_7_8
 		bool "gdb 7.8.x"