ASoC: simple-scu-card: depends on CONFIG_OF

simple-scu-card driver is under CONFIG_OF. This patch adds missing
config.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/Kconfig

@@ -9,6 +9,7 @@ config SND_SIMPLE_CARD
 
 config SND_SIMPLE_SCU_CARD
 	tristate "ASoC Simple SCU sound card support"
+	depends on OF
 	select SND_SIMPLE_CARD_UTILS
 	help
 	  This option enables generic simple SCU sound card support.