x86: Switch all boards to use DM SCSI

After MMC is converted to DM, convert to use DM SCSI as well for all
x86 boards and imply BLK for both MMC and SCSI drivers.

CONFIG_SCSI_DEV_LIST is no longer used. Clean them up.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/qemu/Kconfig b/arch/x86/cpu/qemu/Kconfig
index b6297f7..fdf5ae3 100644
--- a/arch/x86/cpu/qemu/Kconfig
+++ b/arch/x86/cpu/qemu/Kconfig
@@ -8,6 +8,7 @@
 	bool
 	select ARCH_EARLY_INIT_R
 	imply ENV_IS_NOWHERE
+	imply AHCI_PCI
 	imply E1000
 	imply SYS_NS16550
 	imply USB