kconfig: openthread: set Thread 1.4 by default

set `OPENTHREAD_THREAD_VERSION_1_4` as default Thread version in
NCS.

Signed-off-by: Maciej Baczmanski <[email protected]>

Author: maciejbaczmanski

subsys/net/openthread/Kconfig.defconfig

@@ -11,7 +11,7 @@
 if NET_L2_OPENTHREAD
 
 choice OPENTHREAD_STACK_VERSION
-	default OPENTHREAD_THREAD_VERSION_1_3
+	default OPENTHREAD_THREAD_VERSION_1_4
 endchoice
 
 config OPENTHREAD_LIBRARY_AVAILABLE