cros_ec: sandbox: Add Chrome OS EC emulation

Add a simple emulation of the Chrome OS EC for sandbox, so that it can
perform various EC tasks such as keyboard handling.

Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c77e40a..c25e92d 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -11,6 +11,7 @@
 obj-$(CONFIG_CROS_EC) += cros_ec.o
 obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o
 obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
+obj-$(CONFIG_CROS_EC_SANDBOX) += cros_ec_sandbox.o
 obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
 obj-$(CONFIG_FSL_IIM) += fsl_iim.o
 obj-$(CONFIG_GPIO_LED) += gpio_led.o