Adapt dockerfile build args

ARG keyword can only be used right above the parametrized line

.github/workflows/build-docker.yml

@@ -36,5 +36,5 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           tags: ${{ steps.meta.outputs.tags }}
           build-args: |-
-            CONFIG=target/snitch_cluster/cfg/snax-mac.hjson
+            config=cfg/snax-mac.hjson
             SNITCH_LLVM_VERSION=latest

container/Dockerfile

@@ -1,15 +1,15 @@
 # Courtesy of Federico Ficarelli
 
-ARG config=target/snitch_cluster/cfg/default.hjson
 
 FROM ghcr.io/pulp-platform/snitch_cluster:latest@sha256:aa0d9a25022d1ef51f451dc667b850e3e8dba4c15d949b51b5cfde10f89defe9 as builder
 
+ARG config=cfg/default.hjson
 RUN git clone https://github.com/kuleuven-micas/snitch_cluster.git /src \
  && cd /src \
  && git reset --hard 56a9660c97dc7424062534a68af8b26a0844fef3 \
  && git submodule update --init \
  # verilator model
- && make CFG_OVERRIDE=$config -C target/snitch_cluster bin/snitch_cluster.vlt -j$(nproc)
+ && echo $config && make CFG_OVERRIDE=$config -C target/snitch_cluster bin/snitch_cluster.vlt -j$(nproc)
  # spike-dasm
 RUN cd /src/target/snitch_cluster/work-vlt/riscv-isa-sim \
  && ./configure --prefix=/opt/snitch-spike \