staging: crystalhd: add missing fixes for userspace lib build

I somehow managed to not actually include these two fixes in the submission
that was committed to the staging tree. libcrystalhd should eventually be
built against the kernel-provided header, and needs the stdint.h include. The
VOID bit is to keep things in sync with the Mac OS X driver and library that
Scott Davilla is also working on.

Signed-off-by: Scott Davilla <davilla@4pi.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>