ASoC: max98357a: Show KConfig entry

The SEI510 board features a standalone MAX98357A codec.
Add a tristate prompt to allow selecting the codec.
Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/Kconfig

@@ -714,7 +714,8 @@ config SND_SOC_MAX98095
        tristate
 
 config SND_SOC_MAX98357A
-       tristate
+	tristate "Maxim MAX98357A CODEC"
+	depends on GPIOLIB
 
 config SND_SOC_MAX98371
        tristate