spi: bfin-sport: Calculate transfer speed unconditionally

spi: bfin-sport: Calculate transfer speed unconditionally

SPI core validates the transfer speed and defaults to spi->max_speed_hz in
case the transfer speed is not set so code here won't use the
chip->baud value (which is derived from spi->max_speed_hz).

Please note driver uses chip->baud at the beginning of message transmission
by calling the bfin_sport_spi_restore_state() but then programs per
transfer speed in bfin_sport_spi_pump_transfers(). I'm not familiar with
the HW so I don't know would it be possible to remove chip->baud completely
by either using constant value in bfin_sport_spi_restore_state() or by
removing the tclkdiv register write there.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>