qemu_rx: modify twister configuration in board yaml

Enable with zephyr toolchain and set as default.

Signed-off-by: Anas Nashif <[email protected]>

Author: nashif

boards/qemu/rx/qemu_rx.yaml

@@ -9,7 +9,12 @@ simulation:
 arch: rx
 toolchain:
   - cross-compile
+  - zephyr
 supported:
   - serial
 ram: 96
 flash: 512
+testing:
+  default: true
+  only_tags:
+    - kernel