videomodes: Add pixelclock_khz and refresh fields to ctfb_res_modes

videomodes: Add pixelclock_khz and refresh fields to ctfb_res_modes

Add pixelclock_khz and refresh fields to ctfb_res_modes:

1) pixelclocks are usually referred to in hz, not picoseconds, and e.g
pll-s are also typically programmed in hz, not ps. Converting between the
2 leads to rounding differences, add a pixelclock_khz field to directly
store the *exact* pixelclock for a mode, so that drivers do not need to
resort to rounding tricks to try and guess the exact pixelclock;

2) The video-mode environment variable, as parsed by video_get_video_mode
also contains the vertical refresh rate, add a refresh field, so that
the refresh-rate can be matched when parsing the video-mode environment
variable.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Anatolij Gustschin <agust@denx.de>