Convert CONFIG_ENV_IS_IN_SPI_FLASH to Kconfig

This converts the following to Kconfig:
   CONFIG_ENV_IS_IN_SPI_FLASH

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/som-db5800-som-6867_defconfig b/configs/som-db5800-som-6867_defconfig
index 56a7e4b..47daca0 100644
--- a/configs/som-db5800-som-6867_defconfig
+++ b/configs/som-db5800-som-6867_defconfig
@@ -43,7 +43,6 @@
 CONFIG_OF_CONTROL=y
 CONFIG_REGMAP=y
 CONFIG_SYSCON=y
-CONFIG_SCSI=y
 CONFIG_CPU=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_GIGADEVICE=y
@@ -54,6 +53,7 @@
 CONFIG_E1000=y
 CONFIG_DM_PCI=y
 CONFIG_DM_RTC=y
+CONFIG_SCSI=y
 CONFIG_DEBUG_UART_BASE=0x3f8
 CONFIG_DEBUG_UART_CLOCK=1843200
 CONFIG_SYS_NS16550=y