common: Drop linux/bug.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/net/mvpp2.c b/drivers/net/mvpp2.c
index 1e0db6c..8391428 100644
--- a/drivers/net/mvpp2.c
+++ b/drivers/net/mvpp2.c
@@ -26,6 +26,7 @@
 #include <config.h>
 #include <malloc.h>
 #include <asm/io.h>
+#include <linux/bug.h>
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <phy.h>