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_sti_asc.c b/drivers/serial/serial_sti_asc.c
index c972f1e..27d3ec9 100644
--- a/drivers/serial/serial_sti_asc.c
+++ b/drivers/serial/serial_sti_asc.c
@@ -8,6 +8,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <log.h>
 #include <serial.h>
 #include <asm/io.h>