cmd: Add osd commands

Add command to query information from and write text to on-screen
display (OSD) devices.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/gdsys/mpc8308/Kconfig b/board/gdsys/mpc8308/Kconfig
index cb29c25..9d99f68 100644
--- a/board/gdsys/mpc8308/Kconfig
+++ b/board/gdsys/mpc8308/Kconfig
@@ -1,3 +1,9 @@
+config GDSYS_LEGACY_OSD_CMDS
+	bool
+	help
+	  Use the 'osdw', 'osdp', and 'osdsize' legacy commands required by
+	  gdsys devices.
+
 if TARGET_HRCON
 
 config SYS_BOARD
@@ -9,6 +15,9 @@
 config SYS_CONFIG_NAME
 	default "hrcon"
 
+config GDSYS_LEGACY_OSD_CMDS
+	default y
+
 endif
 
 if TARGET_STRIDER
@@ -22,6 +31,8 @@
 config SYS_CONFIG_NAME
 	default "strider"
 
+config GDSYS_LEGACY_OSD_CMDS
+	default y
 endif
 
 config CMD_IOLOOP