ASoC: hdmi-codec: select CONFIG_HDMI

SND_SOC_HDMI_CODEC can be enabled without HDMI support, leading
to a link error:

In function `hdmi_codec_hw_params':
sound/soc/codecs/hdmi-codec.c:188: undefined reference to `hdmi_audio_infoframe_init'
sound/built-in.o:(.debug_addr+0x1a5c0): undefined reference to `hdmi_audio_infoframe_init'

This changes the Kconfig file to select HDMI, as the other codec using
hdmi_audio_infoframe_init already does.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>