ASoC: at91sam9g20ek_2mmc board uses same audio connexion as at91sam9g20ek

The modified revision of at91sam9g20 Evaluation Kit rev. C and onwards share
with previous ones its audio connexion to Wolfson wm8731. Modify the SoC file
to extend the machine ID checking.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/atmel/sam9g20_wm8731.c

@@ -207,7 +207,7 @@ static int __init at91sam9g20ek_init(void)
 	struct clk *pllb;
 	int ret;
 
-	if (!machine_is_at91sam9g20ek())
+	if (!(machine_is_at91sam9g20ek() || machine_is_at91sam9g20ek_2mmc()))
 		return -ENODEV;
 
 	/*