Unused 'pxe_key_data' & 'pxe_instance_name' info

This removes references to the pxe driver's 'pxe_key_data' and
'pxe_instance_name' (driver) info, because that information is
never used.

Change-Id: I73c94dab83fb9c72b251e65859475486505bfbc6
Merge "Unused 'pxe_key_data' & 'pxe_instance_name' info"