drm/bridge: imx8mp-hdmi-tx: allow 0.5% margin with selected clock

drm/bridge: imx8mp-hdmi-tx: allow 0.5% margin with selected clock

This allows the hdmi driver to pick e.g. 64.8MHz instead of 65Mhz when we
cannot output the exact frequency, enabling the imx8mp HDMI output to
support more modes

Tested-by: Adam Ford <aford173@gmail.com> #imx8mp-beacon
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240907-hdmi-tolerance-v2-1-b9d7abd89f5c@codewreck.org
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240907-hdmi-tolerance-v2-1-b9d7abd89f5c@codewreck.org