samples: Bluetooth: Replace OVERLAY_CONFIG with EXTRA_CONF_FILE

OVERLAY_CONFIG has been deprecated and replaced by
EXTRA_CONF_FILE. Update samples to reflect that.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>

samples/bluetooth/ccp_call_control_client/README.rst

@@ -29,7 +29,7 @@ Building and Running
 ********************
 
 When building targeting an nrf52 series board with the Zephyr Bluetooth Controller,
-use ``-DOVERLAY_CONFIG=overlay-bt_ll_sw_split.conf`` to enable the required feature support.
+use ``-DEXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf`` to enable the required feature support.
 
 Building for an nrf5340dk
 -------------------------
@@ -75,4 +75,4 @@ Building for a simulated nrf52_bsim
    :zephyr-app: samples/bluetooth/ccp_call_control_client/
    :board: nrf52_bsim
    :goals: build
-   :gen-args: -DOVERLAY_CONFIG=overlay-bt_ll_sw_split.conf
+   :gen-args: -DEXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf

samples/bluetooth/ccp_call_control_client/sample.yaml

@@ -26,5 +26,5 @@ tests:
       - nrf52833dk/nrf52833
       - nrf52840dk/nrf52840
       - nrf52840dongle/nrf52840
-    extra_args: OVERLAY_CONFIG=overlay-bt_ll_sw_split.conf
+    extra_args: EXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf
     tags: bluetooth

samples/bluetooth/ccp_call_control_server/README.rst

@@ -28,7 +28,7 @@ Building and Running
 ********************
 
 When building targeting an nrf52 series board with the Zephyr Bluetooth Controller,
-use ``-DOVERLAY_CONFIG=overlay-bt_ll_sw_split.conf`` to enable the required feature support.
+use ``-DEXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf`` to enable the required feature support.
 
 Building for an nrf5340dk
 -------------------------
@@ -74,4 +74,4 @@ Building for a simulated nrf52_bsim
    :zephyr-app: samples/bluetooth/ccp_call_control_server/
    :board: nrf52_bsim
    :goals: build
-   :gen-args: -DOVERLAY_CONFIG=overlay-bt_ll_sw_split.conf
+   :gen-args: -DEXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf

samples/bluetooth/ccp_call_control_server/sample.yaml

@@ -26,5 +26,5 @@ tests:
       - nrf52833dk/nrf52833
       - nrf52840dk/nrf52840
       - nrf52840dongle/nrf52840
-    extra_args: OVERLAY_CONFIG=overlay-bt_ll_sw_split.conf
+    extra_args: EXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf
     tags: bluetooth