CHROMIUM: video: tegra: Run pll_d at 252mhz for HDMI 640x480

CHROMIUM: video: tegra: Run pll_d at 252mhz for HDMI 640x480

Using a pll_d clock rate of 216MHz yields a 24MHz pixel clock instead of
25.2MHz. This is just under a 5% error. Instead, use a 252MHz pll_d rate,
which generates 25.2MHz exactly.

This makes it more likely that monitors will sync to the emitted signal.

This also fixes HDMI audio issues, since the CTS/N tables are now based
on the actual pixel clock rate, not merely the intended pixel clock rate.

Tested with a 12MHz pll_m rate on Seaboard, all of 32/44.1/48KHz audio,
all video modes supported by the Tegra dc HDMI driver, and a Dell U2410
dislay.

Signed-off-by: Stephen Warren <swarren@nvidia.com>;

BUG=
TEST=

[Stephen Warren, 2011-03-04 21:27:20]

This series of patches implements audio-over-HDMI support:

http://codereview.chromium.org/6625021
http://codereview.chromium.org/6623022
http://codereview.chromium.org/6626025
http://codereview.chromium.org/6632011
http://codereview.chromium.org/6624031
http://codereview.chromium.org/6624032
http://codereview.chromium.org/6623023
http://codereview.chromium.org/6625022

The series requires two other series to be merged first:
* My series to backport upstream ASoC into ChromeOS
  (strictly necessary in all likelihood)
* Robert's series to rework the dc driver
  (perhaps not required; some small amount of merging may be required
  in order to merge this first though)

Note: This particular patch has been submitted for upstream, and has been
conceptually approved, but has not yet been merged, pending running the
resulting code against an HDMI compliance test device.

[Olof Johansson, 2011-03-07 03:42:16]

Thanks, applied.