spi: Rename SPI_SUPPORT to SPI

Rename these options so that CONFIG_IS_ENABLED can be used with them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/kontron_sl28_defconfig b/configs/kontron_sl28_defconfig
index 9abeacd..6630649 100644
--- a/configs/kontron_sl28_defconfig
+++ b/configs/kontron_sl28_defconfig
@@ -17,7 +17,7 @@
 CONFIG_SPL=y
 CONFIG_ENV_OFFSET_REDUND=0x3f0000
 CONFIG_SPL_SPI_FLASH_SUPPORT=y
-CONFIG_SPL_SPI_SUPPORT=y
+CONFIG_SPL_SPI=y
 # CONFIG_PSCI_RESET is not set
 CONFIG_AHCI=y
 CONFIG_DISTRO_DEFAULTS=y