scsi: Forceably finish migration to DM_SCSI

The migration deadline for moving to DM_SCSI was v2023.04. A further
reminder was sent out in August 2023 to the remaining platforms that had
not migrated already, and that a few more over the line (or configs
deleted).

With this commit we:
- Rename CONFIG_DM_SCSI to CONFIG_SCSI.
- Remove all of the non-DM SCSI code. This includes removing other
  legacy symbols and code and removes some legacy non-DM AHCI code.
- Some platforms that had previously been DM_SCSI=y && SCSI=n are now
  fully migrated to DM_SCSI as a few corner cases in the code assumed
  DM_SCSI=y meant SCSI=y.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/efi-x86_app64_defconfig b/configs/efi-x86_app64_defconfig
index e0cfe3e..d6b6c3d 100644
--- a/configs/efi-x86_app64_defconfig
+++ b/configs/efi-x86_app64_defconfig
@@ -21,6 +21,7 @@
 CONFIG_SYS_PBSIZE=532
 CONFIG_CMD_BOOTZ=y
 CONFIG_CMD_PART=y
+# CONFIG_CMD_SCSI is not set
 # CONFIG_CMD_NET is not set
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_TIME=y