drm/stm/dw_mipi_dsi-stm: convert from round_rate() to determine_rate()

drm/stm/dw_mipi_dsi-stm: convert from round_rate() to determine_rate()

The round_rate() clk ops is deprecated, so migrate this driver from
round_rate() to determine_rate() using the Coccinelle semantic patch
on the cover letter of this series.

Acked-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Signed-off-by: Brian Masney <bmasney@redhat.com>
Acked-by: Yannick Fertre <yannick.fertre@foss.st.com>
Link: https://lore.kernel.org/r/20250811-drm-clk-round-rate-v2-6-4a91ccf239cf@redhat.com
Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>