video_osd: Add osd sandbox driver and tests

Add sandbox driver and tests for the new OSD uclass.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 0b20968..af8375e 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -41,6 +41,7 @@
 CONFIG_CMD_GPT_RENAME=y
 CONFIG_CMD_IDE=y
 CONFIG_CMD_I2C=y
+CONFIG_CMD_OSD=y
 CONFIG_CMD_PCI=y
 CONFIG_CMD_READ=y
 CONFIG_CMD_REMOTEPROC=y
@@ -192,6 +193,8 @@
 CONFIG_CONSOLE_TRUETYPE=y
 CONFIG_CONSOLE_TRUETYPE_CANTORAONE=y
 CONFIG_VIDEO_SANDBOX_SDL=y
+CONFIG_OSD=y
+CONFIG_SANDBOX_OSD=y
 CONFIG_WDT=y
 CONFIG_WDT_SANDBOX=y
 CONFIG_FS_CBFS=y