sandbox: Add a test for IRQ

Add a simple sandbox test for this uclass.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 28313e4..d4e8638 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -42,6 +42,7 @@
 obj-$(CONFIG_GDSYS_RXAUI_CTRL) += gdsys_rxaui_ctrl.o
 obj-$(CONFIG_GDSYS_SOC) += gdsys_soc.o
 obj-$(CONFIG_IRQ) += irq-uclass.o
+obj-$(CONFIG_SANDBOX) += irq_sandbox.o
 obj-$(CONFIG_$(SPL_)I2C_EEPROM) += i2c_eeprom.o
 obj-$(CONFIG_IHS_FPGA) += ihs_fpga.o
 obj-$(CONFIG_IMX8) += imx8/