util/crossgcc: Remove obsolete dockerfile

This file was added here before util/docker existed.  Anyone using this
dockerfile should use the coreboot-sdk docker container instead.

Signed-off-by: Martin Roth <martin@coreboot.org>
Change-Id: I7114abc9c91ba2d6fcfef80ae6e7d1a7a3d253cf
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48902
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

util/crossgcc/Dockerfile

@@ -1,37 +0,0 @@
-FROM debian:sid
-MAINTAINER Martin Roth <gaumless@gmail.com>
-
-RUN \
-	useradd -p locked -m coreboot && \
-	apt-get -qq update && \
-	apt-get -qq upgrade && \
-	apt-get -qqy install gcc g++ gnat-6 make patch python diffutils bison \
-		flex git doxygen ccache subversion p7zip-full unrar-free \
-		m4 wget curl bzip2 vim-common cmake xz-utils pkg-config \
-		dh-autoreconf unifont \
-		libssl-dev libgmp-dev zlib1g-dev libpci-dev liblzma-dev \
-		libyaml-dev libncurses5-dev uuid-dev libusb-dev libftdi-dev \
-		libusb-1.0-0-dev libreadline-dev libglib2.0-dev libgmp-dev \
-		libelf-dev libxml2-dev libfreetype6-dev && \
-	apt-get clean
-
-COPY buildgcc Makefile* root/coreboot/util/crossgcc/
-COPY patches/ /root/coreboot/util/crossgcc/patches/
-COPY sum/ /root/coreboot/util/crossgcc/sum/
-COPY tarballs/ /root/coreboot/util/crossgcc/tarballs/
-
-RUN \
-	cd /root/coreboot/util/crossgcc && \
-	make all_without_gdb \
-        	BUILD_LANGUAGES=c,ada CPUS=$(nproc) DEST=/opt/xgcc && \
-	cd /root && \
-	rm -rf coreboot
-
-RUN mkdir /home/coreboot/.ccache && \
-	chown coreboot:coreboot /home/coreboot/.ccache && \
-	mkdir /home/coreboot/cb_build && \
-	chown coreboot:coreboot /home/coreboot/cb_build
-VOLUME /home/coreboot/.ccache
-
-ENV PATH $PATH:/opt/xgcc/bin
-USER coreboot