mem: read hugepage counts from node-specific sysfs path

mem: read hugepage counts from node-specific sysfs path

For non-legacy memory init mode, instead of looking at generic
sysfs path, look at sysfs paths pertaining to each NUMA node
for hugepage counts. Note that per-NUMA node path does not
provide information regarding reserved pages, so we might not
get the best info from these paths, but this saves us from the
whole mapping/remapping business before we're actually able to
tell which page is on which socket, because we no longer require
our memory to be physically contiguous.

Legacy memory init will not use this.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Tested-by: Santosh Shukla <santosh.shukla@caviumnetworks.com>
Tested-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Tested-by: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>