ASoC: jz4740: Add jz4780 support

The jz4780 and jz4740 have very similar i2s blocks.

The slight difference is in Rx/Tx fifos.
And the bitclocks for input/output are different.

This patch adds jz4780 support to the 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>