spi: rzv2m-csi: Get rid of the x_trg{_words} tables

Table x_trg can be replaced with ilog2(), and table x_trg_words
can be replaced with rounddown_pow_of_two().
Replace the tables usage with the corresponding macros.
While at it, remove a couple of unnecessary empty lines.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230718192453.543549-4-fabrizio.castro.jz@renesas.com


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