Remove Storage#power_state

No PhysicalStorage mention power_state. It is not defined in the
schema nor is it a virtual attribute.

Lenovo praser does parse this out but there is nowhere to put the value.
They did add the column to PhysicalServer and PhysicalSwitch, so I think
this was an oversight.

pr for switch: ManageIQ/manageiq-schema#160
pr for server: ManageIQ/manageiq-schema@8e95341

Lets add this field back in once it is in the database schema

product/views/PhysicalStorage.yaml

@@ -29,7 +29,6 @@ col_order:
 - name
 - type
 - health_state
-- power_state
 - asset_detail.product_name
 - asset_detail.manufacturer
 
@@ -41,7 +40,6 @@ headers:
 - Name
 - Type
 - Health State
-- Power State
 - Product Name
 - Manufacturer