net: fill in MODULE_DESCRIPTION()s for cpsw-common

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the TI CPSW switch module.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw-common.c

@@ -90,4 +90,5 @@ int ti_cm_get_macid(struct device *dev, int slave, u8 *mac_addr)
 }
 EXPORT_SYMBOL_GPL(ti_cm_get_macid);
 
+MODULE_DESCRIPTION("TI CPSW Switch common module");
 MODULE_LICENSE("GPL");