Fix board.yml format for Zephyr 4.2.0

- Update board.yml to new Zephyr 4.2 format with 'board:' root key
- Add CONFIG_BOARD_EWS=y to defconfig
- Remove west workspace files (not needed in git)

firmware/canfd_cdc_composite/boards/arm/ews/board.yml

@@ -1,10 +1,5 @@
-identifier: ews
-name: EWS Board
-type: mcu
-arch: arm
-family: stm32
-series: stm32g0x
-socs:
-  - name: stm32g0b1xx
-testing:
-  default: true
+board:
+  name: ews
+  vendor: ews
+  socs:
+    - name: stm32g0b1xx