Cellular: Remove deprecated CellularDevice::stop()

CellularDevice::shutdown() should be used instead.

Author: Kimmo Vaisanen

UNITTESTS/features/cellular/framework/device/cellulardevice/cellulardevicetest.cpp

@@ -191,19 +191,6 @@ TEST_F(TestCellularDevice, test_get_context_list)
     delete dev;
 }
 
-TEST_F(TestCellularDevice, test_stop)
-{
-    FileHandle_stub fh1;
-    CellularDevice *dev = new myCellularDevice(&fh1);
-    EXPECT_TRUE(dev);
-
-    CellularStateMachine_stub::nsapi_error_value = NSAPI_ERROR_OK;
-    ASSERT_EQ(dev->attach_to_network(), NSAPI_ERROR_OK);
-
-    dev->stop();
-    delete dev;
-}
-
 TEST_F(TestCellularDevice, test_cellular_callback)
 {
     FileHandle_stub fh1;

features/cellular/framework/API/CellularDevice.h

@@ -377,12 +377,6 @@ class CellularDevice {
 
 public: //Common functions
 
-    /** Stop the current operation. Operations: set_device_ready, set_sim_ready, register_to_network, attach_to_network
-     *
-     */
-    MBED_DEPRECATED_SINCE("mbed-os-5.15", "Use CellularDevice::shutdown() instead.")
-    void stop();
-
     /** Get the current FileHandle item used when communicating with the modem.
      *
      *  @return reference to FileHandle

features/cellular/framework/device/CellularDevice.cpp

@@ -64,12 +64,6 @@ CellularDevice::~CellularDevice()
     delete _state_machine;
 }
 
-void CellularDevice::stop()
-{
-    MBED_ASSERT(_state_machine);
-    _state_machine->stop();
-}
-
 FileHandle &CellularDevice::get_file_handle() const
 {
     return *_fh;