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/usb/host/xhci-omap.c b/drivers/usb/host/xhci-omap.c
index 25b195f..501129d 100644
--- a/drivers/usb/host/xhci-omap.c
+++ b/drivers/usb/host/xhci-omap.c
@@ -9,6 +9,7 @@
  */
 
 #include <common.h>
+#include <log.h>
 #include <usb.h>
 #include <linux/errno.h>
 #include <asm/omap_common.h>