MIPS: JZ4770: GCW0: Set PLL1 to 432 MHz

432 MHz is the least common multiple of 27 MHz (required by TV encoder)
and 48 MHz (required by USB host).
video: displays: nt39016: Reduced lines between vsync and display start

This makes it possible to run with 250 lines per frame instead of 262.
fb: JZ4770: Change LCD timing to get exactly 60 Hz

The panel timings are a bit unconventional, but it works fine with our
panel and it avoids stutters when applications wait both on timers and
on vsync.

These timings might not work with TV-out, but we'll deal with that
once TV-out is actually implemented.