v2x: added exit criteria when no v2x module was found on the usb bus

the v2x service won't fail anymore if no modem is found on the usb
bus.

BugzID: 72787

Signed-off-by: Marc Mattmueller <marc.mattmueller@netmodule.com>

recipes-bsp/v2x-ieee802.11p/files/v2x-fw-load

@@ -13,6 +13,10 @@ echo 0 > $HUB_RST
 echo 0 > $V2X_RST
 
 timeout 30 bash -c -- 'while true; do lsusb | grep "0483:df11"; if [ $? == 0  ]; then break; fi; done'
+if [ $? == 124 ]; then
+    echo "v2x module is not available on usb bus"
+    exit 0
+fi
 
 output=$(dfu-util -d 0483:df11 -s 0x10000000 -D /lib/firmware/v2x/SECTON.packed_bin.rom 2>&1)
 err=$?