ASoC: jz4740: Add DT support to jz4740-i2s driver

This patch adds device tree support for the jz4740 driver.

Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>