Fails to link due to missing 'XOpenDisplay' et al.

--- qemu-2.12.0/target/lm32/Makefile.objs.old	2018-04-24 11:30:47.000000000 -0500
+++ qemu-2.12.0/target/lm32/Makefile.objs	2018-07-03 04:12:04.080000000 -0500
@@ -2,3 +2,5 @@
 obj-y += gdbstub.o
 obj-y += lm32-semi.o
 obj-$(CONFIG_SOFTMMU) += machine.o
+
+helper.o-libs := -lX11