fbdev: Fix incorrect timings in some modedb entries

Reported by: John Lumby <johnlumby@hotmail.com>

Some of the entries in the mode database does not match the comments and/or
the refresh field.  Adjust the timings so they match with both the comments
and the refresh rate.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>