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/env/Kconfig b/env/Kconfig
index 24966f8..6dc8d8d 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -357,54 +357,31 @@
 	  different sector sizes, and CONFIG_ENV_SECT_SIZE should be
 	  set to that value.
 
-config USE_ENV_SPI_BUS
-	bool "SPI flash bus for environment"
-	depends on ENV_IS_IN_SPI_FLASH
-	help
-	  Force the SPI bus for environment.
-	  If not defined, use CONFIG_SF_DEFAULT_BUS.
-
 config ENV_SPI_BUS
 	int "Value of SPI flash bus for environment"
-	depends on USE_ENV_SPI_BUS
+	depends on ENV_IS_IN_SPI_FLASH
+	default SF_DEFAULT_BUS
 	help
 	  Value the SPI bus and chip select for environment.
 
-config USE_ENV_SPI_CS
-	bool "SPI flash chip select for environment"
-	depends on ENV_IS_IN_SPI_FLASH
-	help
-	  Force the SPI chip select for environment.
-	  If not defined, use CONFIG_SF_DEFAULT_CS.
-
 config ENV_SPI_CS
 	int "Value of SPI flash chip select for environment"
-	depends on USE_ENV_SPI_CS
+	depends on ENV_IS_IN_SPI_FLASH
+	default SF_DEFAULT_CS
 	help
 	  Value of the SPI chip select for environment.
 
-config USE_ENV_SPI_MAX_HZ
-	bool "SPI flash max frequency for environment"
-	depends on ENV_IS_IN_SPI_FLASH
-	help
-	  Force the SPI max work clock for environment.
-	  If not defined, use CONFIG_SF_DEFAULT_SPEED.
-
 config ENV_SPI_MAX_HZ
 	int "Value of SPI flash max frequency for environment"
-	depends on USE_ENV_SPI_MAX_HZ
+	depends on ENV_IS_IN_SPI_FLASH
+	default SF_DEFAULT_SPEED
 	help
 	  Value of the SPI max work clock for environment.
 
-config USE_ENV_SPI_MODE
-	bool "SPI flash mode for environment"
-	depends on ENV_IS_IN_SPI_FLASH
-	help
-	  Force the SPI work mode for environment.
-
 config ENV_SPI_MODE
 	hex "Value of SPI flash work mode for environment"
-	depends on USE_ENV_SPI_MODE
+	depends on ENV_IS_IN_SPI_FLASH
+	default SF_DEFAULT_MODE
 	help
 	  Value of the SPI work mode for environment.
 	  See include/spi.h for value.