Add comments to explain the types

Signed-off-by: Stephen Sun <[email protected]>

Author: stephenxs

sonic_platform_base/sfp_base.py

@@ -52,6 +52,10 @@ class SfpBase(device_base.DeviceBase):
         SFP_ERROR_BIT_BAD_CABLE:               SFP_ERROR_DESCRIPTION_BAD_CABLE
     }
 
+    # Port types that are used by the chassis API ChassisBase.get_port_or_cage_type()
+    # It's possible that multiple types are supported on one port.
+    # In that case, the result will be logical OR of all the supported types
+    # Check example in ChassisBase.get_port_or_cage_type()
     SFP_PORT_TYPE_BIT_RJ45                = 0x00000001
     SFP_PORT_TYPE_BIT_SFP                 = 0x00000002
     SFP_PORT_TYPE_BIT_XFP                 = 0x00000004