ASoC: fsl: remove redundant Kconfig option SND_SOC_FSL_SSI

While commit 606d620 (ASoC: imx: merge sound/soc/imx into sound/soc/fsl)
adds SND_SOC_FSL_SSI outside "menuconfig SND_POWERPC_SOC" to make it
visible for both PowerPC and ARM/IMX, it forgot removing the one inside
"menuconfig SND_POWERPC_SOC".
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/fsl/Kconfig

@@ -16,10 +16,6 @@ if SND_POWERPC_SOC
 config SND_MPC52xx_DMA
 	tristate
 
-config SND_SOC_FSL_SSI
-	tristate
-	depends on FSL_SOC
-
 config SND_SOC_POWERPC_DMA
 	tristate
 	depends on FSL_SOC