drm/bridge: anx7625: Tune K value for IVO panel

IVO panel require less input video clock variation than video clock
variation in DP CTS spec.

This patch decreases the K value of ANX7625 which will shrink eDP Tx
video clock variation to meet IVO panel's requirement.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210806104407.2208538-1-xji@analogixsemi.com