[posix] add argument to set max power table (#4878)

This commit adds a max power table for POSIX platform, which can
customize the max allowed transmit power of each channel with the
command line argument --max-power-table.

.github/workflows/simulation.yml

@@ -150,6 +150,7 @@ jobs:
       run: |
         sudo apt --no-install-recommends install -y expect ninja-build
         ./script/test build expect
+        VIRTUAL_TIME=0 NODE_MODE=rcp ./script/test clean build expect
     - name: Codecov
       uses: codecov/codecov-action@v1