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>
Series-changes: 2
- Use CONFIG_DM_SCSI instead of mix of DM_SCSI and DM_SATA
  Ceva sata has never used sata commands that's why keep it in
  SCSI part only.
- Separate scsi_scan() for DM_SCSI and do not change cmd/scsi.c
- Extend platdata

Series-changes: 3
- Fix scsi_scan return path
- Fix header location uclass-internal.h
- Add scsi_max_devs under !DM_SCSI
- Add new header device-internal because of device_probe()
- Redesign block device creation algorithm
- Use device_unbind in error path
- Create block device with id and lun numbers (lun was there in v2)
- Cleanup dev_num initialization in block device description
  with fixing parameters in blk_create_devicef
- Create new Kconfig menu for SATA/SCSI drivers
- Extend description for DM_SCSI
- Fix Kconfig dependencies
- Fix kernel doc format in scsi_platdata
- Fix ahci_init_one - vendor variable

Series-changes: 4
- Fix Kconfig entry
- Remove SPL ifdef around SCSI uclass
- Clean ahci_print_info() ifdef logic