ASoC: rockchip: Add rockchip SPDIF transceiver driver

Add a driver for the SPDIF transceiver available on RK3066, RK3188 and
RK3288. Heavily based on the rockchip i2s driver.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/rockchip/Makefile b/sound/soc/rockchip/Makefile
index e9ba558..c0bf560 100644
--- a/sound/soc/rockchip/Makefile
+++ b/sound/soc/rockchip/Makefile
@@ -1,7 +1,9 @@
 # ROCKCHIP Platform Support
 snd-soc-rockchip-i2s-objs := rockchip_i2s.o
+snd-soc-rockchip-spdif-objs := rockchip_spdif.o
 
 obj-$(CONFIG_SND_SOC_ROCKCHIP_I2S) += snd-soc-rockchip-i2s.o
+obj-$(CONFIG_SND_SOC_ROCKCHIP_SPDIF) += snd-soc-rockchip-spdif.o
 
 snd-soc-rockchip-max98090-objs := rockchip_max98090.o
 snd-soc-rockchip-rt5645-objs := rockchip_rt5645.o