ARM: dts: vf610: add remaining SAI instaces

This adds the remaining SAI instances SAI0, SAI1 and SAI3. All
instances are very similar, except that the DMA channel of SAI3
is available on MUX1 (compared to MUX0 for SAI0-SAI2). Also,
SAI3 has a slightly different memory map due to a deeper FIFO,
however in practice the current driver works for SAI3 fine.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>