sandbox: Add a test for SCSI

Add a simple uclass test for SCSI. It reads the partition table from a
disk image and checks that it looks correct.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/Makefile b/test/dm/Makefile
index 7543df8..5178daa 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -91,6 +91,7 @@
 obj-$(CONFIG_DM_RNG) += rng.o
 obj-$(CONFIG_DM_RTC) += rtc.o
 obj-$(CONFIG_SCMI_FIRMWARE) += scmi.o
+obj-$(CONFIG_SCSI) += scsi.o
 obj-$(CONFIG_DM_SERIAL) += serial.o
 obj-$(CONFIG_DM_SPI_FLASH) += sf.o
 obj-$(CONFIG_SIMPLE_BUS) += simple-bus.o