video: sandbox: Enable all colour depths

For sandbox we want to have the maximum possible build coverage, so enable
all colour depths for video.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 50ab365..d7e62be 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -38,6 +38,7 @@
 config VIDEO_BPP8
 	bool "Support 8-bit-per-pixel displays"
 	depends on DM_VIDEO
+	default y if SANDBOX || X86
 	help
 	  Support drawing text and bitmaps onto a 8-bit-per-pixel display.
 	  Enabling this will include code to support this display. Without
@@ -47,6 +48,7 @@
 config VIDEO_BPP16
 	bool "Support 16-bit-per-pixel displays"
 	depends on DM_VIDEO
+	default y if SANDBOX || X86
 	help
 	  Support drawing text and bitmaps onto a 16-bit-per-pixel display.
 	  Enabling this will include code to support this display. Without
@@ -56,7 +58,7 @@
 config VIDEO_BPP32
 	bool "Support 32-bit-per-pixel displays"
 	depends on DM_VIDEO
-	default y if X86
+	default y if SANDBOX || X86
 	help
 	  Support drawing text and bitmaps onto a 32-bit-per-pixel display.
 	  Enabling this will include code to support this display. Without