net: fill in MODULE_DESCRIPTION()s for fec

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the FEC (MPC8xx) Ethernet controller.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Wei Fang <wei.fang@nxp.com>
Link: https://lore.kernel.org/r/20240123190332.677489-8-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/fec_main.c

@@ -4769,4 +4769,5 @@ static struct platform_driver fec_driver = {
 
 module_platform_driver(fec_driver);
 
+MODULE_DESCRIPTION("NXP Fast Ethernet Controller (FEC) driver");
 MODULE_LICENSE("GPL");