net: fill in MODULE_DESCRIPTION()s for ieee802154/fakelb

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the IEEE 802.15.4 loopback driver.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240214152741.670178-3-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ieee802154/fakelb.c

@@ -259,4 +259,5 @@ static __exit void fake_remove_module(void)
 
 module_init(fakelb_init_module);
 module_exit(fake_remove_module);
+MODULE_DESCRIPTION("IEEE 802.15.4 loopback driver");
 MODULE_LICENSE("GPL");