staging: board: disable as it breaks the build

Cc: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/board/Kconfig

 config STAGING_BOARD
 	boolean "Staging Board Support"
 	depends on OF_ADDRESS
+	depends on BROKEN
 	help
 	  Select to enable per-board staging support code.