tf-a: remove zip files to reduce the image size

We don't use android binaries, SGI575/SGM775 platforms and don't need to keep
the zip files bundled in the container.
It reduces the images size from 16.5G to 6.5G.

Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>
Change-Id: I1da73cf73e48ba98a19e06fd08658761eecadf56
diff --git a/bionic-amd64-tf-a-build/Dockerfile b/bionic-amd64-tf-a-build/Dockerfile
index e0d1583..11f1e53 100644
--- a/bionic-amd64-tf-a-build/Dockerfile
+++ b/bionic-amd64-tf-a-build/Dockerfile
@@ -135,7 +135,9 @@
 RUN mkdir -p nfs/downloads/linaro/${LINARO_VERSION} \
     && cd nfs/downloads/linaro/${LINARO_VERSION} \
     && wget -q -c -m -A .zip -np -nd https://releases.linaro.org/members/arm/platforms/${LINARO_VERSION}/ \
-    && for file in *.zip; do unzip -q ${file} -d $(basename ${file} .zip); done
+    && rm -f *-android-*.zip sg*.zip \
+    && for file in *.zip; do unzip -q ${file} -d $(basename ${file} .zip); done \
+    && rm -f *.zip
 
 EXPOSE 22
 ENTRYPOINT ["/usr/sbin/setup-sshd"]