ASoC: Remove name_prefix unset during DAI link init hack again

This was initially removed in commit 6479f15a ("ASoC: Remove name_prefix unset
during DAI link init hack"), but was brought back in commit 503ae5e0 ("ASoC:
core: Add helpers for dai link and aux dev init") by accident. This patch
removes it again.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>