remoproc: stm32: migrate trace to log macro

Define LOG_CATEGORY and remove unneeded pr_fmt macro with the dev
macro as dev->name is displayed and CONFIG_LOGF_FUNC can be
activated for log macro.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

drivers/remoteproc/stm32_copro.c

@@ -2,7 +2,8 @@
 /*
  * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
  */
-#define pr_fmt(fmt) "%s: " fmt, __func__
+#define LOG_CATEGORY UCLASS_REMOTEPROC
+
 #include <common.h>
 #include <dm.h>
 #include <errno.h>