powerpc/t104xd4rdb: add DS26522 nodes to device tree

DS26522 is used for tdm, configured by SPI bus.
Add nodes under spi node to t104xd4rdb.dtsi.

Signed-off-by: Zhao Qiang <qiang.zhao@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>