Add Catalyst 3560-CX-12PC-S Front and Rear image (#2132)

* Catalyst 3560-CX-12PC-S: Set is_powered

* Catalyst 3560-CX-12PC-S: Add front and rear image

* Fixed issues

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Co-authored-by: Harry <Harry@cadby.co.uk>

device-types/Cisco/WS-C3560CX-12PC-S.yaml

@@ -4,6 +4,9 @@ model: Catalyst 3560-CX-12PC-S
 slug: cisco-ws-c3560cx-12pc-s
 part_number: WS-C3560CX-12PC-S
 is_full_depth: false
+is_powered: true
+front_image: true
+rear_image: true
 u_height: 1
 interfaces:
   - name: GigabitEthernet1/0/1

device-types/Cisco/WS-C3560CX-12TC-S.yaml

@@ -5,6 +5,7 @@ slug: cisco-ws-c3560cx-12tc-s
 part_number: WS-C3560CX-12TC-S
 is_full_depth: false
 u_height: 1
+is_powered: true
 interfaces:
   - name: GigabitEthernet1/0/1
     type: 1000base-t