ASoC: spear: Normalise module names

Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/spear/Makefile

 # SPEAR Platform Support
-obj-$(CONFIG_SND_SPEAR_SOC) += spear_pcm.o
-obj-$(CONFIG_SND_SPEAR_SPDIF_IN) += spdif_in.o
-obj-$(CONFIG_SND_SPEAR_SPDIF_OUT) += spdif_out.o
+snd-soc-spear-pcm-objs := spear_pcm.o
+snd-soc-spear-spdif-in-objs := spdif_in.o
+snd-soc-spear-spdif-out-objs := spdif_out.o
+
+obj-$(CONFIG_SND_SPEAR_SOC) += snd-soc-spear-pcm.o
+obj-$(CONFIG_SND_SPEAR_SPDIF_IN) += snd-soc-spear-spdif-in.o
+obj-$(CONFIG_SND_SPEAR_SPDIF_OUT) += snd-soc-spear-spdif-out.o