headers_check fix: x86, mtrr.h

fix the following 'make headers_check' warning:

  usr/include/asm/mtrr.h:61: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

arch/x86/include/asm/mtrr.h

@@ -23,6 +23,7 @@
 #ifndef _ASM_X86_MTRR_H
 #define _ASM_X86_MTRR_H
 
+#include <linux/types.h>
 #include <linux/ioctl.h>
 #include <linux/errno.h>