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-ring.c b/drivers/usb/host/xhci-ring.c
index 3cd6c8a..b6b7c29 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -15,6 +15,7 @@
 
 #include <common.h>
 #include <cpu_func.h>
+#include <log.h>
 #include <asm/byteorder.h>
 #include <usb.h>
 #include <asm/unaligned.h>