Port-mapping for 7.1 devices fails with the null-pointer exception, whenever the device contains the if-cap that are not present in the ModelMappingUtils.

• Modify the code to avoid for such null-pointer exceptions. This is code change is only needed for 7.1. The other two models have necessary code to avoid the null-pointer exception.
• Add the support for If-OTU4-ODU4 supported capability.