We deprecated open coding of the transfer queue back in 2017 so it's high
time we finished up converting drivers to use the standard message queue
code. The mpc52xx-psc driver is fairly straightforward so convert to use
transfer_one_message(), it looks like the driver would be a good fit for
transfer_one() with a little bit of updating but this smaller change seems
safer.

The driver seems like a good candidate for transfer_one() but the chip
select function is actually doing rather more than just updating the chip
select and both transfer_one() and transfer_one_message() are current APIs
so leave that refactoring for another day, ideally by someone with the
hardware.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220613121946.136193-1-broonie@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>