Dockerfile: Add m68k-softmmu to qemu

Given efforts to add an m68k target to CI, build qemu for it.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/tools/docker/Dockerfile b/tools/docker/Dockerfile
index fdcb0c7..2d94ed9 100644
--- a/tools/docker/Dockerfile
+++ b/tools/docker/Dockerfile
@@ -182,7 +182,7 @@
 	git config user.email u-boot@denx.de && \
 	# manually apply the bug fix for QEMU 6.1.0 Xilinx Zynq UART emulation codes
 	wget -O - http://patchwork.ozlabs.org/project/qemu-devel/patch/20210823020813.25192-2-bmeng.cn@gmail.com/mbox/ | git am && \
-	./configure --prefix=/opt/qemu --target-list="aarch64-softmmu,arm-softmmu,i386-softmmu,mips-softmmu,mips64-softmmu,mips64el-softmmu,mipsel-softmmu,ppc-softmmu,riscv32-softmmu,riscv64-softmmu,sh4-softmmu,x86_64-softmmu,xtensa-softmmu" && \
+	./configure --prefix=/opt/qemu --target-list="aarch64-softmmu,arm-softmmu,i386-softmmu,m68k-softmmu,mips-softmmu,mips64-softmmu,mips64el-softmmu,mipsel-softmmu,ppc-softmmu,riscv32-softmmu,riscv64-softmmu,sh4-softmmu,x86_64-softmmu,xtensa-softmmu" && \
 	make -j$(nproc) all install && \
 	rm -rf /tmp/qemu