sandbox: Convert to use driver model for SCSI

At present sandbox is producing a warning about SCSI migration. Drop the
legacy code and replace it with a new implementation.

Also drop the SATA command, which does not work with driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index a834402..a2eb7af 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -85,7 +85,6 @@
 CONFIG_DEBUG_DEVRES=y
 CONFIG_ADC=y
 CONFIG_ADC_SANDBOX=y
-CONFIG_SYS_SATA_MAX_DEVICE=2
 CONFIG_AXI=y
 CONFIG_AXI_SANDBOX=y
 CONFIG_CLK=y
@@ -175,9 +174,7 @@
 CONFIG_SANDBOX_RESET=y
 CONFIG_DM_RTC=y
 CONFIG_SCSI=y
-CONFIG_SCSI_AHCI_PLAT=y
-CONFIG_SYS_SCSI_MAX_SCSI_ID=8
-CONFIG_SYS_SCSI_MAX_LUN=4
+CONFIG_DM_SCSI=y
 CONFIG_SANDBOX_SERIAL=y
 CONFIG_SOUND=y
 CONFIG_SOUND_SANDBOX=y