pcm: add chmap option to route plugin
pcm: add chmap option to route plugin

Add a config definition "chmap" to override the channel maps in the same
way as in the hw and null plugins.

Signed-off-by: Jonas Holmberg <22f3175d4d175237423c359d8d1389838e105c4e@axis.com>
Signed-off-by: Takashi Iwai <4596b3305151c7ee743192a95d394341e3d3b644@suse.de>

tiwai/alsa-lib,alsa-project/alsa-lib,alsa-project/alsa-lib,takaswie/alsa-lib,takaswie/alsa-lib,takaswie/alsa-lib,takaswie/alsa-lib,alsa-project/alsa-lib,takaswie/alsa-lib,tiwai/alsa-lib,tiwai/alsa-lib,tiwai/alsa-lib,alsa-project/alsa-lib