xfsprogs: move __u*/__s* typedefs to per-port headers

xfsprogs: move __u*/__s* typedefs to per-port headers

Currently we have to install the autoconf-generated platform_defs.h
to get the defintions for these.  But they are clearly a feature
of Linux vs non-Linux platforms so move them to the per-port headers
instead.

Note: in the long run it might be a good idea to just the standard
uint*_t/int*_t types instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>