spi: rzv2h-rspi: Simplify clock rate search function signatures

spi: rzv2h-rspi: Simplify clock rate search function signatures

The spr_min and spr_max parameters passed to
rzv2h_rspi_find_rate_variable() and rzv2h_rspi_find_rate_fixed() were
always called with RSPI_SPBR_SPR_MIN and RSPI_SPBR_SPR_MAX respectively.
There is no need to pass these as parameters since the valid SPR range
is fixed by the hardware.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://patch.msgid.link/20260410080517.2405700-4-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>