Fix broken cellular_device test and delete commented code

Author: felser

features/cellular/framework/targets/MultiTech/DragonflyNano/PPP/SARA4_PPP.cpp

@@ -37,31 +37,13 @@ SARA4_PPP::~SARA4_PPP()
 {
 }
 
-CellularNetwork *SARA4_PPP::open_network(FileHandle *fh)
+AT_CellularNetwork *SARA4_PPP::open_network_impl(ATHandler &at)
 {
-    if (!_network) {
-        ATHandler *atHandler = get_at_handler(fh);
-        if (atHandler) {
-            _network = new SARA4_PPP_CellularNetwork(*atHandler);
-            if (!_network) {
-                release_at_handler(atHandler);
-            }
-        }
-    }
-    return _network;
+    return new SARA4_PPP_CellularNetwork(at);
 }
 
-CellularPower *SARA4_PPP::open_power(FileHandle *fh)
+AT_CellularPower *SARA4_PPP::open_power_impl(ATHandler &at)
 {
-    if (!_power) {
-        ATHandler *atHandler = get_at_handler(fh);
-        if (atHandler) {
-            _power = new SARA4_PPP_CellularPower(*atHandler);
-            if (!_power) {
-                release_at_handler(atHandler);
-            }
-        }
-    }
-    return _power;
+    return new SARA4_PPP_CellularPower(at);
 }
 

features/cellular/framework/targets/MultiTech/DragonflyNano/PPP/SARA4_PPP.h

@@ -29,8 +29,8 @@ class SARA4_PPP : public AT_CellularDevice {
     virtual ~SARA4_PPP();
 
 public: // CellularDevice
-    virtual CellularNetwork *open_network(FileHandle *fh);
-    virtual CellularPower *open_power(FileHandle *fh);
+    virtual AT_CellularNetwork *open_network_impl(ATHandler &at);
+    virtual AT_CellularPower *open_power_impl(ATHandler &at);
 };
 
 } // namespace mbed

features/cellular/framework/targets/MultiTech/DragonflyNano/PPP/SARA4_PPP_CellularNetwork.cpp

@@ -34,15 +34,7 @@ bool SARA4_PPP_CellularNetwork::get_modem_stack_type(nsapi_ip_stack_t requested_
 
 AT_CellularNetwork::RegistrationMode SARA4_PPP_CellularNetwork::has_registration(RegistrationType reg_type)
 {
-//<<<<<<< HEAD
     return (reg_type == C_REG || reg_type == C_GREG) ? RegistrationModeLAC : RegistrationModeDisable;
-//=======
-//#ifdef TARGET_DRAGONFLY_L471QG
-//    return (reg_type == C_REG || reg_type == C_EREG);
-//#else
-//    return (reg_type == C_REG || reg_type == C_GREG || reg_type == C_EREG);
-//#endif
-//>>>>>>> Fixed spacing/tabs and clean up targets.json
 }
 
 nsapi_error_t SARA4_PPP_CellularNetwork::set_access_technology_impl(RadioAccessTechnology opRat)