ASoC: WM8903: Disallow all invalid gpio_cfg pdata values

The GPIO registers are 15 bits wide. Hence values, higher than 0x7fff are
not legal GPIO register values. Modify the pdata.gpio_cfg handling code
to reject all illegal values, not just WM8903_GPIO_NO_CONFIG (0x8000). This
will allow the later use of 0xffffffff as an invalid value in future device
tree bindings, meaning "don't touch this GPIO's configuration".
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm8903.c

@@ -1936,11 +1936,11 @@ static int wm8903_probe(struct snd_soc_codec *codec)
 		bool mic_gpio = false;
 
 		for (i = 0; i < ARRAY_SIZE(pdata->gpio_cfg); i++) {
-			if (pdata->gpio_cfg[i] == WM8903_GPIO_NO_CONFIG)
+			if (pdata->gpio_cfg[i] > 0x7fff)
 				continue;
 
 			snd_soc_write(codec, WM8903_GPIO_CONTROL_1 + i,
-				      pdata->gpio_cfg[i] & 0xffff);
+				      pdata->gpio_cfg[i] & 0x7fff);
 
 			val = (pdata->gpio_cfg[i] & WM8903_GP1_FN_MASK)
 				>> WM8903_GP1_FN_SHIFT;