ci: add iperf

Author: frank-w

.github/workflows/build.yml

@@ -99,6 +99,12 @@ jobs:
           sudo chroot ${{ env.CHROOT }} /usr/local/bin/build_iproute2.sh
           cp ${{ env.CHROOT }}/usr/src/iproute2/iproute2.tar.gz ./iproute2_${{ env.ARCH }}.tar.gz
 
+      - name: build iperf3 (arm64)
+        run: |
+          sudo cp build_iperf3.sh ${{ env.CHROOT }}/usr/local/bin/
+          sudo chroot ${{ env.CHROOT }} /usr/local/bin/build_iperf3.sh
+          cp ${{ env.CHROOT }}/usr/src/iperf/iperf.tar.gz ./iperf_${{ env.ARCH }}.tar.gz
+
       - name: build swconfig (arm64)
         run: |
           sudo cp swconfig_includes/switch.h ${{ env.CHROOT }}/usr/include/linux/