clk: define LOG_CATEGORY for generic and ccf clocks

Define LOG_CATEGORY to allow filtering with log command
for generic clock and CCF clocks.

This patch also change existing printf, debug and pr_ macro
to log_ or dev_ macro.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
diff --git a/drivers/clk/clk_fixed_rate.c b/drivers/clk/clk_fixed_rate.c
index c5a2a42..b5e78c7 100644
--- a/drivers/clk/clk_fixed_rate.c
+++ b/drivers/clk/clk_fixed_rate.c
@@ -3,9 +3,12 @@
  * Copyright (C) 2016 Masahiro Yamada <yamada.masahiro@socionext.com>
  */
 
+#define LOG_CATEGORY UCLASS_CLK
+
 #include <common.h>
 #include <clk-uclass.h>
 #include <dm.h>
+#include <log.h>
 #include <dm/device-internal.h>
 #include <linux/clk-provider.h>