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/configs/sandbox_spl_defconfig b/configs/sandbox_spl_defconfig
index a713494..87223a5 100644
--- a/configs/sandbox_spl_defconfig
+++ b/configs/sandbox_spl_defconfig
@@ -199,6 +199,7 @@
 CONFIG_SPMI_SANDBOX=y
 CONFIG_SYSINFO=y
 CONFIG_SYSINFO_SANDBOX=y
+CONFIG_SYSINFO_GPIO=y
 CONFIG_SYSRESET=y
 CONFIG_SPL_SYSRESET=y
 CONFIG_TIMER=y