Add benchmarking to baremetal CI for M55-AN547

Run benchmarks with PMU cycle counting in the baremetal CI workflow
for the M55-AN547 target. The benchmarks run in QEMU which doesn't
emulate the PMU, so cycle counts will be zero, but this tests that
the benchmark code compiles and runs correctly.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mkannwischer

.github/workflows/baremetal.yml

@@ -24,6 +24,7 @@ jobs:
            kat: true
            acvp: true
            alloc: true
+           bench: true
          - runner: ubuntu-latest
            name: 'AVR ATmega128RFR2 (modified for 32K RAM)'
            makefile: test/baremetal/platform/avr/platform.mk
@@ -32,6 +33,7 @@ jobs:
            kat: true
            acvp: true
            alloc: false
+           bench: false
     runs-on: ${{ matrix.target.runner }}
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
@@ -49,3 +51,11 @@ jobs:
           examples: false
           stack: false
           alloc: ${{ matrix.target.alloc }}
+      - name: Baremetal bench
+        if: ${{ matrix.target.bench }}
+        shell: ${{ env.SHELL }}
+        env:
+          EXTRA_MAKEFILE: ${{ matrix.target.makefile }}
+        run: |
+          make clean
+          ./scripts/tests bench --opt=NO_OPT