wrong macro in configure.ac for intel driver?

[Drew Parsons]

Debian bug #380112 at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=380112 suggests that
AC_CHECK_HEADER should be used instead of AC_CHECK_FILE in
xf86-video-intel's configure.ac, or else cross-compiling fails.

Could you confirm this is correct?  If so, then I'll be happy to apply
the patch.

Thanks,
Drew