bug.h: add include of it to various implicit C users

With bug.h currently living right in linux/kernel.h there
are files that use BUG_ON and friends but are not including
the header explicitly.  Fix them up so we can remove the
presence in kernel.h file.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/mips/fw/arc/cmdline.c b/arch/mips/fw/arc/cmdline.c
index 9fdf07e..c0122a1 100644
--- a/arch/mips/fw/arc/cmdline.c
+++ b/arch/mips/fw/arc/cmdline.c
@@ -7,6 +7,7 @@
  *
  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
  */
+#include <linux/bug.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
diff --git a/arch/mips/fw/arc/identify.c b/arch/mips/fw/arc/identify.c
index 788060a..54a33c7 100644
--- a/arch/mips/fw/arc/identify.c
+++ b/arch/mips/fw/arc/identify.c
@@ -11,6 +11,7 @@
  *
  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
  */
+#include <linux/bug.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/types.h>