southbridge/intel: Move spi driver to use spi_bus_map

This is in preparation to get rid of the strong spi_setup_slave
implemented by different platforms.

BUG=b:38430839

Change-Id: I23c1108c85532b7346ff7e0adb0ac90dbf2bb2cc
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19779
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
diff --git a/src/southbridge/intel/common/spi.c b/src/southbridge/intel/common/spi.c
index be9b128..13db224 100644
--- a/src/southbridge/intel/common/spi.c
+++ b/src/southbridge/intel/common/spi.c
@@ -941,10 +941,12 @@
 	.flash_probe = spi_flash_programmer_probe,
 };
 
-int spi_setup_slave(unsigned int bus, unsigned int cs, struct spi_slave *slave)
-{
-	slave->bus = bus;
-	slave->cs = cs;
-	slave->ctrlr = &spi_ctrlr;
-	return 0;
-}
+const struct spi_ctrlr_buses spi_ctrlr_bus_map[] = {
+	{
+		.ctrlr = &spi_ctrlr,
+		.bus_start = 0,
+		.bus_end = 0,
+	},
+};
+
+const size_t spi_ctrlr_bus_map_count = ARRAY_SIZE(spi_ctrlr_bus_map);