Improve c906 smart qemu support

Author: rcitach

.github/ALL_BSP_COMPILE.json

@@ -470,6 +470,13 @@
       "SUB_RTT_BSP": [
         "xuantie/smartl/e906"
       ]
+    },
+    {
+      "RTT_BSP": "xuantie-smart",
+      "RTT_TOOL_CHAIN": "sourcery-Xuantie-900-gcc-linux-musl",
+      "SUB_RTT_BSP": [
+        "xuantie/virt64/c906"
+      ]
     }
   ]
 }

.github/workflows/bsp_buildings.yml

@@ -159,6 +159,14 @@ jobs:
           /opt/Xuantie-900-gcc-elf-newlib-x86_64-V3.0.2/bin/riscv64-unknown-elf-gcc --version
           echo "RTT_EXEC_PATH=/opt/Xuantie-900-gcc-elf-newlib-x86_64-V3.0.2/bin" >> $GITHUB_ENV
 
+      - name: Install Xuantie-900-gcc-linux-musl Tools
+        if: ${{ matrix.legs.RTT_TOOL_CHAIN == 'sourcery-Xuantie-900-gcc-linux-musl' && success() }}
+        run: |
+          wget -q https://github.com/RT-Thread/toolchains-ci/releases/download/v1.9/Xuantie-900-gcc-linux-6.6.0-musl64-x86_64-V3.0.2.tar.gz
+          sudo tar -zxvf Xuantie-900-gcc-linux-6.6.0-musl64-x86_64-V3.0.2.tar.gz -C /opt
+          /opt/Xuantie-900-gcc-linux-6.6.0-musl64-x86_64-V3.0.2/bin/riscv64-unknown-linux-musl-gcc --version
+          echo "RTT_EXEC_PATH=/opt/Xuantie-900-gcc-linux-6.6.0-musl64-x86_64-V3.0.2/bin" >> $GITHUB_ENV
+
       - name: Install k230 MUSL ToolChains
         if: ${{ matrix.legs.RTT_TOOL_CHAIN == 'riscv64-unknown-linux-musl-' && matrix.legs.RTT_BSP == 'K230' && success() }}
         run: |