spi: lpspi: release requested DMA channels

The requested DMA channels are never released. Do this in .remove as well
as in .probe. spi_register_controller() can return -EPROBE_DEFER if
cs-gpios are not probed yet.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20211109103134.184216-1-alexander.stein@ew.tq-group.com


Signed-off-by: Mark Brown <broonie@kernel.org>