Dockerfile: remove coreboot dir after build to save space

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>

Dockerfile

@@ -30,14 +30,14 @@ RUN wget https://github.com/LongSoft/UEFITool/releases/download/A59/UEFIExtract_
     mv UEFIExtract /usr/local/bin && \
     rm UEFIExtract_NE_A59_linux_x86_64.zip
 
-RUN git clone https://github.com/coreboot/coreboot.git \
-      -b master \
-      --depth 1 && \
+RUN git clone https://github.com/coreboot/coreboot.git && \
     cd coreboot && \
     git checkout 497fea7d673b201b044a70baeb93ef04e175fa58 && \
     cd util/cbfstool && \
     make && \
-    make install
+    make install && \
+    cd ../../../ && \
+    rm -rf coreboot
 
 # Build vboot tools. We should use a common revision of vboot tools there,
 # which is known to support correctly all of the Dasharo platforms.