Correct permissions on /tftpdboot/pxelinux.cfg directory

Elements current setting of 744 casuses nodes to encounter a boot
error when attempting to tftp boot with Ironic. This patch corrects
the error. Also changes permissions on ironic /mnt/state/var/lib/ironic
from 744 to 755.

Change-Id: I9879f60a6d1f0fe075ebfa96d0bfafeb9d8127c6
Merge "Correct permissions on /tftpdboot/pxelinux.cfg directory"