1. Add new structure spi_ctrlr_buses that allows platform to define a
mapping from SPI controller to buses managed by the controller.
2. Provide weak implementations of spi_init and spi_setup_slave that
will be used by platforms using the new interface.
BUG=chrome-os-partner:59832
BRANCH=None
TEST=Compiles successfully
Change-Id: Ia6f47941b786299f4d823895898ffb1b36e02f73
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/17561
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
b5d41cb063