kernel: fix kmod-wireguard package fields

Use NETWORK_SUPPORT_MENU like all other modules in netsupport.mk. Drop
SECTION and CATEGORY fields as they are set by default and to match
other packages in netsupport.mk. Use better TITLE for kmod-wireguard
(taken from upstream drivers/net/Kconfig).

Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>