omap3: decrease cpufreq transition latency

Adjust OMAP3 frequency transition latency from 10,000,000uS to a more
reasonable 300,000uS.  This causes ondemand and conservative governors to
sample CPU load more often resulting in more responsive behavior.

Tested on Android 2.6.29; using this value and conservative governor, CORE
power consumption on Zoom2 was comparable to the old and unresponsive
10,000,000uS value while UI responsiveness was greatly improved.

This patch applies against Tony's omap-fixes branch.

Signed-off-by: Mike Turquette <mturquette@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>