Convert CONFIG_SCSI to Kconfig

This converts the following to Kconfig:
   CONFIG_SCSI

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/omap5_uevm_defconfig b/configs/omap5_uevm_defconfig
index f5ac38b..0af00b1 100644
--- a/configs/omap5_uevm_defconfig
+++ b/configs/omap5_uevm_defconfig
@@ -32,6 +32,7 @@
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_ISO_PARTITION=y
+CONFIG_SCSI=y
 CONFIG_DFU_MMC=y
 CONFIG_DFU_RAM=y
 CONFIG_MMC_OMAP_HS=y