VOL-1394: Reverse the pbit map string before parsing it to create the list gem_entity_ids for the 8021p mapper

Change-Id: I06576de5f01d543d34ac4654808e8cde7d26046c
diff --git a/voltha/adapters/brcm_openomci_onu/omci/brcm_tp_service_specific_task.py b/voltha/adapters/brcm_openomci_onu/omci/brcm_tp_service_specific_task.py
index 3e0178c..0df8d80 100644
--- a/voltha/adapters/brcm_openomci_onu/omci/brcm_tp_service_specific_task.py
+++ b/voltha/adapters/brcm_openomci_onu/omci/brcm_tp_service_specific_task.py
@@ -347,7 +347,7 @@
 
                 if gem_port.direction == "upstream" or \
                         gem_port.direction == "bi-directional":
-                    for i, p in enumerate(gem_port.pbit_map):
+                    for i, p in enumerate(reversed(gem_port.pbit_map)):
                         if p == '1':
                             gem_entity_ids[i] = gem_port.entity_id
                 elif gem_port.direction == "downstream":