The current scheme for audio card names is suboptimal because it causes
the automatically generated names (for ID and driver) to be truncated,
which in turn can cause conflicts.

Introduce a new scheme which reuses the board model for the names and
appends the "HDA" and "APE" suffixes for the HDA and APE, respectively.
As a side-effect these suffixes end up being used as the ID of the SoC
sound cards which makes it easy for users to select them when using the
ALSA command-line utilities, for example.

As a separate measure, the driver name for the cards is now set by the
corresponding audio driver (either tegra-hda or tegra-ape), making it a
more useful identifier than the currently normalized card name.
Signed-off-by: Thierry Reding <treding@nvidia.com>