i2c: OMAP3: Better noise suppression for fast/standard modes

Use longer noise filter period for fast and standard mode. Based on an
earlier patch by Eero Nurkkala.

Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>