ASoC: tegra: remove support of legacy DMA driver based access

Remove the support code which uses the legacy APB DMA driver
for accessing the I2S FIFO.
The driver will use the dmaengine based APB DMA driver for
accessing reqding/writing to I2S FIFO.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>