Add elevation images to F5 BIG-IP i5000 series (#1633)

Co-authored-by: Rafał Sulkowski <rafal.sulkowski@wroclaw.sa.gov.pl>

device-types/F5/BIG-IP-i5600.yaml

@@ -7,6 +7,9 @@ u_height: 1
 is_full_depth: true
 weight: 76
 weight_unit: lb
+airflow: front-to-rear
+front_image: true
+rear_image: true
 comments: '[F5 BIG-IP Systems](https://www.f5.com/pdf/products/big-ip-platforms-datasheet.pdf)'
 console-ports:
   - name: Console

device-types/F5/BIG-IP-i5800.yaml

@@ -5,6 +5,9 @@ slug: f5-big-ip-i5800
 part_number: i5800
 u_height: 1
 is_full_depth: true
+airflow: front-to-rear
+front_image: true
+rear_image: true
 console-ports:
   - name: Console
     type: rj-45