mem: share hugepage info primary and secondary

mem: share hugepage info primary and secondary

Since we are going to need to map hugepages in both primary and
secondary processes, we need to know where we should look for
hugetlbfs mountpoints. So, share those with secondary processes,
and map them on init.

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>