test: Add gpio-sysinfo test

This adds a test for the gpio-sysinfo driver.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/Makefile b/test/dm/Makefile
index e7cb1ee..c964461 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -96,6 +96,7 @@
 obj-y += syscon.o
 obj-$(CONFIG_RESET_SYSCON) += syscon-reset.o
 obj-$(CONFIG_SYSINFO) += sysinfo.o
+obj-$(CONFIG_SYSINFO_GPIO) += sysinfo-gpio.o
 obj-$(CONFIG_TEE) += tee.o
 obj-$(CONFIG_TIMER) += timer.o
 obj-$(CONFIG_DM_USB) += usb.o