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/common/usb_storage.c b/common/usb_storage.c
index aba9ccb..743a239 100644
--- a/common/usb_storage.c
+++ b/common/usb_storage.c
@@ -37,6 +37,7 @@
 #include <command.h>
 #include <dm.h>
 #include <errno.h>
+#include <log.h>
 #include <mapmem.h>
 #include <memalign.h>
 #include <asm/byteorder.h>