Add support for a new "SPI" device type in the devicetree to bind a
device on the SPI bus. Allow device to provide chip select number for
the device as a parameter.
Add spi_bus_operations with operation dev_to_bus which allows SoCs to
define a translation method for converting "struct device" into a unique
SPI bus number.
BUG=chrome-os-partner:59832
BRANCH=None
TEST=Compiles successfully.
Change-Id: I86f09516d3cddd619fef23a4659c9e4eadbcf3fa
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/18340
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: build bot (Jenkins)
