dm: video: Add an EFI framebuffer driver

This adds a DM video driver for U-Boot as the EFI payload. The driver
makes use of all necessary information from the passed EFI GOP info
to create a linear framebuffer device, as if it were initialized by
U-Boot itself.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 4c4d286..5ee9032 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -156,6 +156,15 @@
 	  coreboot already. This can in principle be used with any platform
 	  that coreboot supports.
 
+config VIDEO_EFI
+	bool "Enable EFI framebuffer driver support"
+	depends on EFI_STUB
+	help
+	  Turn on this option to enable a framebuffeer driver when U-Boot is
+	  loaded as a payload (see README.u-boot_on_efi) by an EFI BIOS where
+	  the graphics device is configured by the EFI BIOS already. This can
+	  in principle be used with any platform that has an EFI BIOS.
+
 config VIDEO_VESA
 	bool "Enable VESA video driver support"
 	default n