Convert CONFIG_ENV_SPI_BUS et al to Kconfig

This converts the following to Kconfig:
   CONFIG_ENV_SPI_BUS
   CONFIG_ENV_SPI_CS
   CONFIG_ENV_SPI_MAX_HZ
   CONFIG_ENV_SPI_MODE

As part of this, we use Kconfig to provide the defaults now that were
done in include/spi_flash.h.  We also in some cases change from using
CONFIG_ENV_SPI_FOO to CONFIG_SF_DEFAULT_FOO as those were the values in
use anyhow as ENV was not enabled.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/net/pfe_eth/pfe_firmware.c b/drivers/net/pfe_eth/pfe_firmware.c
index ad5bc3c..93e5ea5 100644
--- a/drivers/net/pfe_eth/pfe_firmware.c
+++ b/drivers/net/pfe_eth/pfe_firmware.c
@@ -179,10 +179,10 @@
 	if (!addr)
 		return -ENOMEM;
 
-	ret = spi_flash_probe_bus_cs(CONFIG_ENV_SPI_BUS,
-				     CONFIG_ENV_SPI_CS,
-				     CONFIG_ENV_SPI_MAX_HZ,
-				     CONFIG_ENV_SPI_MODE,
+	ret = spi_flash_probe_bus_cs(CONFIG_SYS_FSL_PFE_SPI_BUS,
+				     CONFIG_SYS_FSL_PFE_SPI_CS,
+				     CONFIG_SYS_FSL_PFE_SPI_MAX_HZ,
+				     CONFIG_SYS_FSL_PFE_SPI_MODE,
 				     &new);
 	if (ret) {
 		printf("SF: failed to probe spi\n");