board: st: common: migrate trace to dev and log macro

Change pr_* to dev_ or log_ macro and define LOG_CATEGORY.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/board/st/common/stusb160x.c b/board/st/common/stusb160x.c
index e0a2b76..f0385e5 100644
--- a/board/st/common/stusb160x.c
+++ b/board/st/common/stusb160x.c
@@ -6,6 +6,8 @@
  * Copyright (C) 2020, STMicroelectronics - All Rights Reserved
  */
 
+#define LOG_CATEGORY UCLASS_I2C_GENERIC
+
 #include <common.h>
 #include <dm.h>
 #include <i2c.h>