As noted by Dennis Chen, we don't want to print "No NUMA configuration
found" if NUMA was forced off from the command line.

Change the type of numa_off to bool, and clean up printing code.
Print "NUMA disabled" if forced off on command line and "No NUMA
configuration found" if there was no firmware NUMA information.
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dennis Chen <dennis.chen@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>