spi: spi-mem: Check the controller extra capabilities

Controllers can now provide a spi-mem capabilities structure. Let's make
use of it in spi_mem_controller_default_supports_op(). As we want to
check for DTR operations as well as normal operations in a single
helper, let's pull the necessary checks from spi_mem_dtr_supports_op()
for now.

However, because no controller provide these extra capabilities, this
change has no effect so far.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-3-miquel.raynal@bootlin.com