Update config Section

1. QoS config update
2. UPF configuration update
3. UE address allocation notes cleanup

Change-Id: Ibdeb0f54a25fd39da094b03ad2f762812592c0e7
diff --git a/configuration/config_upf.rst b/configuration/config_upf.rst
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+..
+   SPDX-FileCopyrightText: © 2022 Open Networking Foundation <support@opennetworking.org>
+   SPDX-License-Identifier: Apache-2.0
+
+UPF Configuration
+=================
+
+Below you may find some of the upf override configuration.
+
+Bess default values `can be found here <https://gerrit.opencord.org/plugins/gitiles/sdfabric-helm-charts/+/refs/heads/master/bess-upf/values.yaml>`_
+
+UPF Address Pool
+-----------------
+
+Below config is basic minimal config which has UE address pool configuration
+.. code-block::
+
+  config:
+    upf:
+      cfgFiles:
+        upf.json:
+          mode: af_packet  #this mode means no dpdk
+          hwcksum: true
+          log_level: "trace"
+          gtppsc: true #extension header is enabled in 5G. Sending QFI in pdu session extension header
+          measure_upf: false #enable packet processing time
+          cpiface:
+            dnn: "internet" #keep it matching with Slice dnn
+            hostname: "upf"
+            #http_port: "8080"
+            enable_ue_ip_alloc: true # if true then it means UPF allocates address from below pool
+            ue_ip_pool: "172.250.0.0/16" # UE ip pool is used if enable_ue_ip_alloc is set to true
+
+
+Slice rate Configuration
+------------------------
+
+.. code-block::
+
+  config:
+    upf:
+      cfgFiles:
+        upf.json:
+          # Default global rate limits. Can be changed at runtime via BESS gRPC.
+          slice_rate_limit_config:
+            # Uplink
+            n6_bps: 1000000000 # 1Gbps
+            n6_burst_bytes: 12500000 # 10ms * 1Gbps
+            # Downlink
+            n3_bps: 1000000000 # 1Gbps
+            n3_burst_bytes: 12500000 # 10ms * 1Gbps
+
+.. note::
+  TBD : add REST api documentation to change slice QoS rates.
+
+UPF Enable dpdk & sriov
+------------------------
+
+.. code-block::
+
+  config:
+    upf:
+      # Enable privileged when run from VM with sriov support
+      privileged: false
+      hugepage:
+        enabled: true
+      sriov:
+        enabled: true
+      cniPlugin: vfioveth
+      access:
+        # Provide sriov resource name when sriov is enabled
+        resourceName: "intel.com/intel_sriov_vfio"
+      core:
+        # Provide sriov resource name when sriov is enabled
+        resourceName: "intel.com/intel_sriov_vfio"
+      cfgFiles:
+        upf.json:
+          mode: dpdk