drm/bridge: cdns-dsi: Fix the clock variable for mode_valid()

The crtc_* mode parameters do not get generated (duplicated in this
case) from the regular parameters before the mode validation phase
begins.

The rest of the code conditionally uses the crtc_* parameters only
during the bridge enable phase, but sticks to the regular parameters
for mode validation. In this singular instance, however, the driver
tries to use the crtc_clock parameter even during the mode validation,
causing the validation to fail.

Allow the D-Phy config checks to use mode->clock instead of
mode->crtc_clock during mode_valid checks, like everywhere else in the
driver.

Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework")
Cc: stable@vger.kernel.org
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Signed-off-by: Aradhya Bhatia <aradhya.bhatia@linux.dev>
Link: https://lore.kernel.org/r/20250329113925.68204-4-aradhya.bhatia@linux.dev
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>