fbdev: da8xx:: fix reporting of the display timing info

fbdev: da8xx:: fix reporting of the display timing info

Timing info is not properly reported by the driver, e.g.:

$ fbset -i
mode "480x272-35"
    # D: 7.895 MHz, H: 12.165 kHz, V: 35.158 Hz
    geometry 480 272 480 544 16
    timings 126666 64 64 32 32 41 10

According to the timing values defined for LK043T1DG01 display
it should be reported as:

mode "480x272-53"
    # D: 7.895 MHz, H: 15.038 kHz, V: 52.579 Hz
    geometry 480 272 480 544 16
    timings 126666 2 2 2 2 41 10

Initialize additional fb_var_screeninfo fields so fix this problem.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Manjunathappa, Prakash <prakash.pm@ti.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>