ASoC imx-audmux: add MX31_AUDMUX_PORT7_SSI_PINS_7 define

The MX31 Audmux also has 7 Ports.
This patch adds the missing define, and makes the debugfs code iterate
over that port too.

Signed-off-by: Torben Hohn <torbenh@linutronix.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/fsl/imx-audmux.h

@@ -14,6 +14,7 @@
 #define MX31_AUDMUX_PORT4_SSI_PINS_4	3
 #define MX31_AUDMUX_PORT5_SSI_PINS_5	4
 #define MX31_AUDMUX_PORT6_SSI_PINS_6	5
+#define MX31_AUDMUX_PORT7_SSI_PINS_7	6
 
 #define MX51_AUDMUX_PORT1_SSI0		0
 #define MX51_AUDMUX_PORT2_SSI1		1