Move clippy into seperate workflow

.github/workflows/check.yml

@@ -12,15 +12,10 @@ jobs:
           target: thumbv6m-none-eabi
           override: true
           profile: minimal
-          components: clippy
       - uses: actions-rs/cargo@v1
         with:
           command: check
           args: --workspace
-      - uses: actions-rs/cargo@v1
-        with:
-          command: clippy
-          args: -- -Dwarnings
       - uses: actions-rs/cargo@v1
         with:
           command: test

.github/workflows/clippy.yml

@@ -0,0 +1,18 @@
+on: [push, pull_request]
+name: Clippy check
+jobs:
+  clippy_check:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          target: thumbv6m-none-eabi
+          override: true
+          profile: minimal
+          components: clippy
+      - uses: actions-rs/cargo@v1
+        with:
+          command: clippy
+          args: -- -Dwarnings