net: 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/net/eth-uclass.c b/net/eth-uclass.c
index 5146bd6..c2a97d7 100644
--- a/net/eth-uclass.c
+++ b/net/eth-uclass.c
@@ -5,6 +5,8 @@
  * Joe Hershberger, National Instruments
  */
 
+#define LOG_CATEGORY UCLASS_ETH
+
 #include <common.h>
 #include <bootstage.h>
 #include <dm.h>