boards/renesas: adapt to zephyr SDK toolchain name change

Signed-off-by: Keith Packard <[email protected]>

Author: keith-packard

boards/renesas/rsk_rx130/rsk_rx130_512kb.yaml

@@ -8,6 +8,7 @@ arch: rx
 toolchain:
   - cross-compile
   - zephyr
+  - zephyr-gnu
 supported:
   - gpio
   - serial