common: Drop log.h from common header

Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/serial_mtk.c b/drivers/serial/serial_mtk.c
index e63f230..778a04d 100644
--- a/drivers/serial/serial_mtk.c
+++ b/drivers/serial/serial_mtk.c
@@ -11,6 +11,7 @@
 #include <div64.h>
 #include <dm.h>
 #include <errno.h>
+#include <log.h>
 #include <serial.h>
 #include <watchdog.h>
 #include <asm/io.h>