Disable the cell AUX UART by default on EP_AGORA

Author: Chris Trowbridge

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/TARGET_MCU_NRF52840/TARGET_EP_AGORA/ONBOARD_TELIT_ME910.cpp

@@ -114,7 +114,7 @@ nsapi_error_t ONBOARD_TELIT_ME910::init()
     // AT#PORTCFG=0
     // Set command allows to connect Service Access Points to the external physical ports giving a great
     // flexibility. Examples of Service Access Points: AT Parser Instance #1, #2, #3, etc..
-    _at->at_cmd_discard("#PORTCFG", "=3");
+    _at->at_cmd_discard("#PORTCFG", "=", "%d", EP_AGORA_PORT_CONFIGURATION_VARIANT);
 
     // AT&W&P
     // - AT&W: Execution command stores on profile <n> the complete configuration of the device. If

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/TARGET_MCU_NRF52840/TARGET_EP_AGORA/mbed_lib.json

@@ -5,6 +5,11 @@
             "help"                 : "Enable the cell module on the EP_AGORA board",
             "macro_name"           : "EP_AGORA_ENABLE_CELL",
             "value"                : true
+        },
+        "port-configuration-variant" : {
+            "help"                 : "Telit ME910C1 AT#PORTCFG Variant value",
+            "macro_name"           : "EP_AGORA_PORT_CONFIGURATION_VARIANT",
+            "value"                : 0
         }
     },
     "target_overrides": {