Dockerfile: Build a copy of QEMU and install it under /opt

In order to run our test.py suite on a number of platforms in CI we use
QEMU.  Configure and build a copy here so that all our jobs can rely on
it as our code is under test and not QEMU.
Signed-off-by: Tom Rini <trini@konsulko.com>

Dockerfile

@@ -76,6 +76,14 @@ RUN apt-get update && apt-get install -y \
 	zip \
 	&& rm -rf /var/lib/apt/lists/*
 
+RUN git clone git://git.qemu.org/qemu.git /tmp/qemu && \
+	cd /tmp/qemu && \
+	git submodule update --init dtc && \
+	git checkout 506179e42112be77bfd071f050b15762d3b2cd43 && \
+	./configure --prefix=/opt/qemu --target-list="aarch64-softmmu,arm-softmmu,i386-softmmu,mips-softmmu,mips64-softmmu,mips64el-softmmu,mipsel-softmmu,ppc-softmmu,x86_64-softmmu,xtensa-softmmu" && \
+	make -j$(nproc) all install && \
+	rm -rf /tmp/qemu
+
 # Create the buildman config file
 RUN /bin/echo -e "[toolchain]\nroot = /usr" > ~/.buildman
 RUN /bin/echo -e "kernelorg = /opt/gcc-7.3.0-nolibc/*" >> ~/.buildman