make MTD headers use strict integer types

The MTD headers traditionally use stdint types rather than
the kernel integer types. This converts them to do the
same as all the others.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>