dm: sandbox: Add a simple driver to test of-platdata

Add a driver which uses of-platdata to obtain its platform data. This can
be used to test the feature in sandbox. It displays the contents of its
platform data.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 066639b..3eac024 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -35,6 +35,11 @@
 obj-$(CONFIG_SMSC_SIO1007) += smsc_sio1007.o
 obj-$(CONFIG_STATUS_LED) += status_led.o
 obj-$(CONFIG_SANDBOX) += swap_case.o
+ifdef CONFIG_SPL_OF_PLATDATA
+ifdef CONFIG_SPL_BUILD
+obj-$(CONFIG_SANDBOX) += spltest_sandbox.o
+endif
+endif
 obj-$(CONFIG_SANDBOX) += syscon_sandbox.o
 obj-$(CONFIG_TWL4030_LED) += twl4030_led.o
 obj-$(CONFIG_FSL_IFC) += fsl_ifc.o