dm: Add support for scsi/sata based devices

All sata based drivers are bind and corresponding block
device is created. Based on this find_scsi_device() is able
to get back block device based on scsi_curr_dev pointer.

intr_scsi() is commented now but it can be replaced by calling
find_scsi_device() and scsi_scan().

scsi_dev_desc[] is commented out but common/scsi.c heavily depends on
it. That's why CONFIG_SYS_SCSI_MAX_DEVICE is hardcoded to 1 and symbol
is reassigned to a block description allocated by uclass.
There is only one block description by device now but it doesn't need to
be correct when more devices are present.

scsi_bind() ensures corresponding block device creation.
uclass post_probe (scsi_post_probe()) is doing low level init.

SCSI/SATA DM based drivers requires to have 64bit base address as
the first entry in platform data structure to setup mmio_base.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>