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/ls2081ardb_defconfig b/configs/ls2081ardb_defconfig
index d8420ba..bc2792e 100644
--- a/configs/ls2081ardb_defconfig
+++ b/configs/ls2081ardb_defconfig
@@ -21,6 +21,7 @@
 CONFIG_OF_CONTROL=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_DM=y
+CONFIG_SCSI=y
 CONFIG_FSL_CAAM=y
 CONFIG_DM_SPI_FLASH=y
 CONFIG_NETDEVICES=y