build: add optional NUMA and CPU counts detection

build: add optional NUMA and CPU counts detection

Add an option to automatically discover the host's NUMA and CPU counts
and use those values for a non cross-build.
Give users the option to override the per-arch default values or values
from cross files by specifying them on the command line with -Dmax_lcores
and -Dmax_numa_nodes.

Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: David Christensen <drc@linux.vnet.ibm.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>