net: eth-phy: define LOG_CATEGORY

Define LOG_CATEGORY to allow filtering with log command.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/drivers/net/eth-phy-uclass.c b/drivers/net/eth-phy-uclass.c
index 293579d..c04bab9 100644
--- a/drivers/net/eth-phy-uclass.c
+++ b/drivers/net/eth-phy-uclass.c
@@ -3,6 +3,8 @@
  * Copyright 2020 NXP
  */
 
+#define LOG_CATEGORY UCLASS_ETH_PHY
+
 #include <common.h>
 #include <dm.h>
 #include <log.h>