[DASH] Add missing prefixes to PL mapping (opencomputeproject#2035)

Two attributes that are needed for calculating
PL overlay SIP and DIP were are added to mask out
portions of those values per mapping

experimental/saiexperimentaldashoutboundcatopa.h

@@ -173,6 +173,16 @@ typedef enum _sai_outbound_ca_to_pa_entry_attr_t
      */
     SAI_OUTBOUND_CA_TO_PA_ENTRY_ATTR_OVERLAY_SIP,
 
+    /**
+     * @brief Action set_private_link_mapping parameter OVERLAY_SIP_MASK
+     *
+     * @type sai_ip_address_t
+     * @flags CREATE_AND_SET
+     * @default 0.0.0.0
+     * @validonly SAI_OUTBOUND_CA_TO_PA_ENTRY_ATTR_ACTION == SAI_OUTBOUND_CA_TO_PA_ENTRY_ACTION_SET_PRIVATE_LINK_MAPPING
+     */
+    SAI_OUTBOUND_CA_TO_PA_ENTRY_ATTR_OVERLAY_SIP_MASK,
+
     /**
      * @brief Action set_private_link_mapping parameter OVERLAY_DIP
      *
@@ -183,6 +193,16 @@ typedef enum _sai_outbound_ca_to_pa_entry_attr_t
      */
     SAI_OUTBOUND_CA_TO_PA_ENTRY_ATTR_OVERLAY_DIP,
 
+    /**
+     * @brief Action set_private_link_mapping parameter OVERLAY_DIP_MASK
+     *
+     * @type sai_ip_address_t
+     * @flags CREATE_AND_SET
+     * @default 0.0.0.0
+     * @validonly SAI_OUTBOUND_CA_TO_PA_ENTRY_ATTR_ACTION == SAI_OUTBOUND_CA_TO_PA_ENTRY_ACTION_SET_PRIVATE_LINK_MAPPING
+     */
+    SAI_OUTBOUND_CA_TO_PA_ENTRY_ATTR_OVERLAY_DIP_MASK,
+
     /**
      * @brief Action set_private_link_mapping parameter DASH_ENCAPSULATION
      *