nrf/bluetooth: Add support for SoftDevice s140 version 6.1.1.

Updating download script to fetch the new SoftDevice, and
adding corresponding linker script for the BLE stack.

ports/nrf/boards/s140_6.1.1.ld

+/* GNU linker script for s140 SoftDevice version 6.1.1 */
+
+_sd_size = 0x00026000;
+_sd_ram  = 0x000039c0;

ports/nrf/drivers/bluetooth/download_ble_stack.sh

@@ -57,6 +57,24 @@ function download_s140_nrf52_6_0_0
     cd -
 }
 
+function download_s140_nrf52_6_1_1
+{
+    echo ""
+    echo "####################################"
+    echo "### Downloading s140_nrf52_6.1.1 ###"
+    echo "####################################"
+    echo ""
+
+    mkdir -p $1/s140_nrf52_6.1.1
+    cd $1/s140_nrf52_6.1.1
+    wget --post-data="fileName=DeviceDownload&ids=CE89BA7633C540AFA48AB88E934DBF05" https://www.nordicsemi.com/api/sitecore/Products/MedialibraryZipDownload2
+    mv MedialibraryZipDownload2 temp.zip
+    unzip -u temp.zip
+    unzip -u s140nrf52611.zip
+    rm s140nrf52611.zip
+    rm temp.zip
+    cd -
+}
 
 SCRIPT_DIR="$(cd -P "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
@@ -65,6 +83,7 @@ if [ $# -eq 0 ]; then
     download_s110_nrf51_8_0_0 ${SCRIPT_DIR}
     download_s132_nrf52_6_1_1 ${SCRIPT_DIR}
     download_s140_nrf52_6_0_0 ${SCRIPT_DIR}
+    download_s140_nrf52_6_1_1 ${SCRIPT_DIR}
 else 
     case $1 in
         "s110_nrf51" )
@@ -73,6 +92,8 @@ else
             download_s132_nrf52_6_1_1 ${SCRIPT_DIR} ;;
         "s140_nrf52_6_0_0" )
             download_s140_nrf52_6_0_0 ${SCRIPT_DIR} ;;
+        "s140_nrf52_6_1_1" )
+            download_s140_nrf52_6_1_1 ${SCRIPT_DIR} ;;
     esac
 fi