drm/omap: tweak HDMI DDC timings

A "HDMI I2C Master Error" is sometimes reported with the current DDC SCL
timings. The current settings for a 10us SCL period (100 KHz) causes the
error with some displays.  This patch increases the SCL signal period
from 10us to 10.2us, with the new settings the error is not observed

Signed-off-by: Alejandro Hernandez <ajhernandez@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190930103840.18970-4-tomi.valkeinen@ti.com