[HA] [cinder] Fix rootfs part name for sda > 2TB

[HA] [cinder] Fix rootfs part name for sda > 2TB

On systems with more than 2TB on /dev/sda, MaaS automatically creates
a 1MB partition with bios_grub label as /dev/sda1.
Account for this and expect rootfs to reside on /dev/sda2 (assume
all compute nodes have the same behavior wrt this issue).

Ideally, later we will switch to explicit partitioning via MaaS, or to
a new baremetal provisioner like Ironic.

Requires bumping Pharos git submodule to pick up the new j2 filter.

Fixes: f6f8a56

JIRA: FUEL-330

Change-Id: I12f5046cf69bf2f52c8b8dc331b90048df643646
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>