ALSA: x86: hdmi: select CONFIG_SND_PCM

The newly added driver uses the PCM helpers and fails to link if they are disabled:

sound/built-in.o: In function `hdmi_lpe_audio_runtime_suspend':
intel_hdmi_audio.c:(.text+0x15906): undefined reference to `snd_pcm_suspend'
sound/built-in.o: In function `had_pcm_hw_params':
intel_hdmi_audio.c:(.text+0x15ac7): undefined reference to `snd_pcm_lib_malloc_pages'
sound/built-in.o: In function `had_pcm_open':
intel_hdmi_audio.c:(.text+0x15d49): undefined reference to `snd_pcm_hw_constraint_integer'

This uses a Kconfig 'select' statement to make sure they are enabled.

Fixes: 5dab11d8 ("ALSA: x86: hdmi: Add audio support for BYT and CHT")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>