docker, runtime: only build clang and llc targets

Specify only the targets we need from the llvm build, namely `clang` and
`llc`. This reduces the amount of objects to build by ~300 and thus
also reduces build time a bit.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

contrib/packaging/docker/Dockerfile.runtime

@@ -58,7 +58,7 @@ cd llvm/ && \
 git checkout -b d941df363d1cb621a3836b909c37d79f2a3e27e2 d941df363d1cb621a3836b909c37d79f2a3e27e2 && \
 cd llvm/build && \
 cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF" -DLLVM_ENABLE_PROJECTS="clang" -DBUILD_SHARED_LIBS=OFF -DCMAKE_BUILD_TYPE=Release -DLLVM_BUILD_RUNTIME=OFF && \
-ninja && \
+ninja clang llc && \
 strip bin/clang && \
 strip bin/llc && \
 cp bin/clang /usr/bin/clang && \