tools/include: use stdint types for user-space byteshift headers

Commit a07f7672

 added user-space copies
of the byteshift headers to be used by hostprogs, changing e.g. u8 to __u8.
However, in order to cross-compile the kernel from a non-Linux system,
stdint.h types need to be used instead of linux/types.h types.

Signed-off-by: Yaakov Selkowitz <yselkowitz@users.sourceforge.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>