ASoC: ep93xx: fix build of ep93xx-ac97.c

Fix the build of this driver. It was broken by:

Commit 453807f3
ASoC: ep93xx: Use ep93xx_dma_params instead of ep93xx_pcm_dma_params

The removed struct ep93xx_pcm_dma_params use the member 'dma_port' to
select the dma channel. The struct ep93xx_dma_data uses the member
'port'.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Mark Brown <broonie@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>