Move Chipyard CI to Github Actions

- As similar as possible to the circle ci code.
- The `.github/README.md` file has a fair amount of documentation for this.
- Creates a worfklow file
  - re-uses most of the circleci/scipts unchanged
  - defines a number of *Composite Actions* which are like YML subroutines
- Removes the circle-ci code
- Points the CI badge in the top level README to use the GA test result

.github/actions/prepare-rtl/action.yml

@@ -2,13 +2,24 @@ name: prepare-rtl
 description: 'Builds RTL based on parameters, caches the entire chipyard root dir when done'
 
 inputs:
+<<<<<<< HEAD
+=======
+  tools-version:
+    description: Which toolchain to build
+    required: false
+    default: 'riscv-tools'
+>>>>>>> 52c752ba... Move Chipyard CI to Github Actions
   group-key:
     description: group key
     required: true
   build-script:
     description: rtl build script to use
     required: false
+<<<<<<< HEAD
     default: "remote-do-rtl-build.sh"
+=======
+    default: "do-rtl-build.sh"
+>>>>>>> 52c752ba... Move Chipyard CI to Github Actions
   build-type:
     description: type of build
     required: false
@@ -17,9 +28,12 @@ inputs:
 runs:
   using: "composite"
   steps:
+<<<<<<< HEAD
     - name: Build RISC-V toolchains
       uses: ./.github/actions/toolchain-build
 
+=======
+>>>>>>> 52c752ba... Move Chipyard CI to Github Actions
     - uses: actions/cache@v2
       id: rtl-build-id
       with:
@@ -28,13 +42,24 @@ runs:
           sims/firesim/sim
           generators/gemmini/software/gemmini-rocc-tests
         key: ${{ inputs.group-key }}-${{ github.ref }}-${{ github.sha }}
+<<<<<<< HEAD
 
     - name: Run RTL build if not cached
+=======
+    - name: run rtl build script if not cached
+>>>>>>> 52c752ba... Move Chipyard CI to Github Actions
       run: |
         if [[ "${{ steps.rtl-build-id.outputs.cache-hit }}" != 'true' ]]; then
           echo "Cache miss on ${{ inputs.group-key }}-${{ github.ref }}-${{ github.sha }}"
           ./.github/scripts/${{ inputs.build-script }} ${{ inputs.group-key }} ${{ inputs.build-type }}
         else
+<<<<<<< HEAD
           echo "Cache hit do not rebuild RTL for ${{ inputs.group-key }}"
         fi
       shell: bash
+=======
+          echo "cache hit do not prepare rtl"
+        fi
+      shell: bash
+
+>>>>>>> 52c752ba... Move Chipyard CI to Github Actions