Update ironic properties to match REST API doc

The referenced doc is here:

http://docs.openstack.org/developer/ironic/webapi/v1.html

This fix should make it far more explicit what units are needed
for various node properties.  Note that Ironic and Nova BareMetal
now use the exact same property names.

Closes-bug: #1342156
Change-Id: I024c29d0ab648ed5db000ddb6d0ffaa24e8805b8