ASoC: add SOC_VALUE_ENUM_EXT

Adds an equivalent of SOC_ENUM_EXT for value enums

Strictly speaking SOC_ENUM_EXT can also be used to define
a value enum since the only difference is the get and set
functions. But this doesn't look good in code because it is
inconsistent with the normal control definitions. Adding a
specific SOC_VALUE_ENUM_EXT is better for code clarity.
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc.h

@@ -248,6 +248,8 @@
 	.info = snd_soc_info_enum_double, \
 	.get = xhandler_get, .put = xhandler_put, \
 	.private_value = (unsigned long)&xenum }
+#define SOC_VALUE_ENUM_EXT(xname, xenum, xhandler_get, xhandler_put) \
+	SOC_ENUM_EXT(xname, xenum, xhandler_get, xhandler_put)
 
 #define SND_SOC_BYTES(xname, xbase, xregs)		      \
 {	.iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname,   \