We are getting inconsistent methods for endian detection (same answer when
it works, just doesn't work on some platforms) depending on whether __GLIBC__
is defined, which of course depends on include ordering before p_config.h
Just make p_config.h include limits.h to solve this.
Signed-off-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Brian Paul <brianp@vmware.com>