libxcb: disable check to avoid floating dependencies
The "check" module is checked for in configure without any way to explicitly
enable or disable it, but it isn't a build dependency of libxcb. If it's found
libxslt is also checked for, which is a build dependency but will only be used
if check is also present.
As the libxcb unit test suite is minimal at present, forcibly disable the test
for check and remove the libxslt-native build dependency.
Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
