ltp-testsuite: disable numa tests

The LTP_CHECK_SYSCALL_NUMA autoconf macro uses AC_RUN_IFELSE when it
detects the numaif.h header. This is incompatible with cross
compilation.

Fixes:
http://autobuild.buildroot.net/results/21a/21a6eeddbf5ccffc34c38527d0807305a5eb3917/
http://autobuild.buildroot.net/results/fc0/fc01921e8e8e1ea100461b29137c4219e6686c58/
http://autobuild.buildroot.net/results/962/96285d154abd65838ff5c66e96db309d9ac26c80/



Cc: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>