Convert CONFIG_CMD_SCSI to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_SCSI

Also update the Makefile to use CONFIG_CMD_SCSI instead of CONFIG_SCSI to
enable the command, fixing an earlier error.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
[trini: Rework to default y if SCSI, drop cl-som-am57x which did not use
CMD_SCSI for real]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ls1012aqds_qspi_defconfig b/configs/ls1012aqds_qspi_defconfig
index 383fc1a..dfc3786 100644
--- a/configs/ls1012aqds_qspi_defconfig
+++ b/configs/ls1012aqds_qspi_defconfig
@@ -29,6 +29,7 @@
 CONFIG_CMD_DATE=y
 CONFIG_CMD_EXT2=y
 CONFIG_CMD_FAT=y
+CONFIG_CMD_SCSI=y
 CONFIG_OF_CONTROL=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_DM=y