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/ep93xx_eth.c b/drivers/net/ep93xx_eth.c
index 5aed164..894ffc9 100644
--- a/drivers/net/ep93xx_eth.c
+++ b/drivers/net/ep93xx_eth.c
@@ -24,6 +24,7 @@
 #include <asm/io.h>
 #include <malloc.h>
 #include <miiphy.h>
+#include <linux/bug.h>
 #include <linux/types.h>
 #include "ep93xx_eth.h"