spi: spi-ti-qspi: Remove unused macro for fclk frequency

The fclk and its rate are retrieved from DT.

Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Ryan Barnett <ryan.barnett@rockwellcollins.com>
Cc: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Cc: Arnout Vandecappelle <arnout.vandecappelle@essensium.com>
Link: https://lore.kernel.org/r/20191211193954.747745-2-jean.pihet@newoldbits.com


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