ASoC: core: Add helpers for codec and codec_dai search

Add dedicated helpers for codec and codec_dai search in preparation
for DAI-multicodec. It will help reducing the extra indentation
that will be introduced by the iteration over multiple codecs.

Previous implementation unnecessarily kept searching for a matching
codec in the remaining register codecs even if it was already found.

Fix that by returning in case of matching.

Signed-off-by: Misael Lopez Cruz <misael.lopez@ti.com>
[fparent@baylibre.com: Adapt to 3.14+]
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Benoit Cousson <bcousson@baylibre.com>
Signed-off-by: Mark Brown <broonie@linaro.org>