The iLO drivers try to set boot mode to UEFI when they detect UEFI-capable hardware.
This can be surprising for operators, as it's not consistent with other drivers.
Also, UEFI support in TripleO is somewhat less mature.
Change the default boot mode to "bios" via puppet. Operators can still change
the boot mode per node by setting an appropriate capability.
Change-Id: Ide26d05289ba962759163a60dab06e5152812dba
Closes-Bug: #1604002