dm: Add Kconfig for driver/demo

Add a suitable Kconfig for this directory.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

drivers/Kconfig

@@ -2,6 +2,8 @@ menu "Device Drivers"
 
 source "drivers/core/Kconfig"
 
+source "drivers/demo/Kconfig"
+
 source "drivers/pci/Kconfig"
 
 source "drivers/pcmcia/Kconfig"

drivers/demo/Kconfig

+config DM_DEMO
+	bool "Enable demo uclass support"
+	depends on DM
+	help
+	  This uclass allows you to play around with driver model. It provides
+	  an interface to a couple of demo devices. You can access it using
+	  the 'demo' command or by calling the uclass functions from your
+	  own code.
+
+config DM_DEMO_SIMPLE
+	bool "Enable simple demo device for driver model"
+	depends on DM_DEMO
+	help
+	  This device allows you to play around with driver model. It prints
+	  a message when the 'demo hello' command is executed which targets
+	  this device. It can be used to help understand how driver model
+	  works.
+
+config DM_DEMO_SHAPE
+	bool "Enable shape demo device for driver model"
+	depends on DM_DEMO
+	help
+	  This device allows you to play around with driver model. It prints
+	  a shape when the 'demo hello' command is executed which targets
+	  this device. It can be used to help understand how driver model
+	  works.