`off_t` is supposed to be signed, but has no (minimum) width
specified. We'll assume 32-bit minimum, like a `signed long int`.
Also include `sys/types.h` in `libpayload.h` so everything is
available through the latter.
Change-Id: I6c0c1bc1a959db7863cbad2ba29318da162431be
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/31346
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>