scsi: Add buffer_aligned check pass-through

Some devices have limited DMA capabilities and require that the
buffers passed to them fit specific properties. Add new optional
callback which can be used at driver level to indicate whether a
buffer alignment is suitable for the device DMA or not. This is
a pass-through callback from block uclass to drivers.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>