Added Cisco Nexus 9508 switch (#2594)

* Added Cisco Nexus 9508 switch with front and rear images

* Update N9K-C9508.yml

---------

Co-authored-by: draket77 <94173365+draket77@users.noreply.github.com>
Co-authored-by: Harry <Harry@cadby.co.uk>

device-types/Cisco/N9K-C9508.yml

@@ -0,0 +1,97 @@
+---
+manufacturer: Cisco
+model: Nexus 9508
+slug: cisco-n9k-c9508
+part_number: N9K-C9508
+front_image: true
+rear_image: true
+u_height: 13
+weight: 68.2
+airflow: front-to-rear
+weight_unit: kg
+is_full_depth: true
+module-bays:
+  - name: Slot 1
+    position: '1'
+    description: Line Card
+  - name: Slot 2
+    position: '2'
+    description: Line Card
+  - name: Slot 3
+    position: '3'
+    description: Line Card
+  - name: Slot 4
+    position: '4'
+    description: Line Card
+  - name: Slot 5
+    position: '5'
+    description: Line Card
+  - name: Slot 6
+    position: '6'
+    description: Line Card
+  - name: Slot 7
+    position: '7'
+    description: Line Card
+  - name: Slot 8
+    position: '8'
+    description: Line Card
+  - name: Slot 21
+    label: Fabric Module 1
+    position: '21'
+  - name: Slot 22
+    label: Fabric Module 2
+    position: '22'
+  - name: Slot 23
+    label: Fabric Module 3
+    position: '23'
+  - name: Slot 24
+    label: Fabric Module 4
+    position: '24'
+  - name: Slot 25
+    label: Fabric Module 5
+    position: '25'
+  - name: Slot 26
+    label: Fabric Module 6
+    position: '26'
+  - name: Slot 27
+    label: Supervisor Module 1
+    position: '27'
+  - name: Slot 28
+    label: Supervisor Module 2
+    position: '28'
+  - name: Slot 29
+    label: System Controller 1
+    position: '29'
+  - name: Slot 30
+    label: System Controller 2
+    position: '30'
+  - name: PS1
+    position: '1'
+    label: Power Supply 1
+  - name: PS2
+    position: '2'
+    label: Power Supply 2
+  - name: PS3
+    position: '3'
+    label: Power Supply 3
+  - name: PS4
+    position: '4'
+    label: Power Supply 4
+  - name: PS5
+    position: '5'
+    label: Power Supply 5
+  - name: PS6
+    position: '6'
+    label: Power Supply 6
+  - name: PS7
+    position: '7'
+    label: Power Supply 7
+  - name: PS8
+    position: '8'
+    label: Power Supply 8
+  - name: Fan 1
+    position: '1'
+  - name: Fan 2
+    position: '2'
+  - name: Fan 3
+    position: '3'