[bare-metal]Ironic miss the configuration about tftp

[Ma Wen Cheng]

# IP address of Ironic compute node's tftp server. (string
# value)
#tftp_server=$my_ip

# Ironic compute node's tftp root path. (string value)
#tftp_root=/tftpboot

# Directory where master tftp images are stored on disk.
# (string value)
#tftp_master_path=/tftpboot/master_images

there is a reference http://docs.openstack.org/developer/ironic/deploy/install-guide.html#pxe-setup

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/176585

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/176585
Committed: https://git.openstack.org/cgit/stackforge/cookbook-openstack-bare-metal/commit/?id=a515f81febe18ee125522b02eaf4acc7cf13ed41
Submitter: Jenkins
Branch: master

commit a515f81febe18ee125522b02eaf4acc7cf13ed41
Author: wenchma <email address hidden>
Date: Thu Apr 23 10:38:50 2015 +0800

    Add tftp configuration for ironic

    Expose the tftp configuration to support tftp, disable by default.

    Change-Id: I9175e420a3def4cf10e95701c235bbae999b6505
    Closes-bug: #1446972