spi: spi-fsl-dspi: delete EOQ transfer mode

After the only user of the limited EOQ mode has now been converted to
DMA as of commit b09058bb ("spi: spi-fsl-dspi: set ColdFire to DMA
mode"), we can finally delete this code.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20200823212657.2400075-1-olteanv@gmail.com


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