wl12xx: Do end-of-transactions transfers only if needed

On newer hardware revisions, there is no need to write the host's
counter at the end of a RX transaction. The same applies to writing the
number of packets at the end of a TX transaction.

It is generally a good idea to avoid unnecessary SDIO/SPI transfers.
Throughput and CPU usage are improved when avoiding these.

Send the host's RX counter and the TX packet count only if needed, based
on the hardware revision.

[Changed WL12XX_QUIRK_END_OF_TRANSACTION to use BIT(0) -- Luca]

Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Reviewed-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>