build hostapd inside chroot

hostapd was not built inside the chroot and could therefore link to libs
on the dev machine instead of those that will be installed on the
DISTRO11S_BOARD.  Fix this by compiling from within the STAGING chroot.
set permission on correct ldconfig binary

There is no ldconfig executable in the root (/) dir, so fix the
permissions to allow execution of /sbin/ldconfig