Makefile: Correct logic for DM_SCSI + unconverted drivers check

When checking for boards that are enabling a SATA driver that isn't
converted to DM yet we need to be sure to not also trip over boards that
do set CONFIG_DM_SCSI by itself, as that is not a bug.

Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Fixes: ea9d7c17fc4c ("dm: MIGRATION: Add migration plan for CONFIG_SATA")
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/Makefile b/Makefile
index eeb299f..dff72a5 100644
--- a/Makefile
+++ b/Makefile
@@ -938,7 +938,8 @@
 	@echo >&2 "===================================================="
 endif
 endif
-ifeq ($(CONFIG_LIBATA)$(CONFIG_DM_SCSI)$(CONFIG_MVSATA_IDE),y)
+ifeq ($(CONFIG_LIBATA)$(CONFIG_MVSATA_IDE),y)
+ifneq ($(CONFIG_DM_SCSI),y)
 	@echo >&2 "===================== WARNING ======================"
 	@echo >&2 "This board does not use CONFIG_DM_SCSI. Please update"
 	@echo >&2 "the storage controller to use CONFIG_DM_SCSI before the v2019.07 release."
@@ -946,6 +947,7 @@
 	@echo >&2 "See doc/driver-model/MIGRATION.txt for more info."
 	@echo >&2 "===================================================="
 endif
+endif
 ifeq ($(CONFIG_OF_EMBED),y)
 	@echo >&2 "===================== WARNING ======================"
 	@echo >&2 "CONFIG_OF_EMBED is enabled. This option should only"