powerpc/of: add eSPI controller dts bindings and DTS modification

Also modifiy the document of cell-index in SPI controller. Add the
SPI flash(s25fl128p01) support on p4080ds and mpc8536ds board.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
3 files changed