[bsp] remove stm32f20x

Author: mysterywolf

.github/workflows/action.yml

@@ -119,7 +119,6 @@ jobs:
          - {RTT_BSP: "stm32/stm32mp157a-st-discovery", RTT_TOOL_CHAIN: "sourcery-arm"}
          - {RTT_BSP: "stm32/stm32mp157a-st-ev1", RTT_TOOL_CHAIN: "sourcery-arm"}
          - {RTT_BSP: "stm32/stm32wb55-st-nucleo", RTT_TOOL_CHAIN: "sourcery-arm"}
-         - {RTT_BSP: "stm32f20x", RTT_TOOL_CHAIN: "sourcery-arm"}
          - {RTT_BSP: "swm320", RTT_TOOL_CHAIN: "sourcery-arm"}
          - {RTT_BSP: "swm320-lq100", RTT_TOOL_CHAIN: "sourcery-arm"}
          - {RTT_BSP: "beaglebone", RTT_TOOL_CHAIN: "sourcery-arm"}