spi: spi-nxp-fspi: use DLL calibration when clock rate > 100MHz

When clock rate > 100MHz, use the DLL calibration mode, and finally
add the suggested half of the current clock cycle to sample the data.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://lore.kernel.org/r/20230322090451.3179431-2-haibo.chen@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>