Lowering hard drive idle timeout to 5 seconds from 20 seconds.

This change saves about 200mW of power on SSDs.

Change-Id: I7a7dfdbd7e264386d21da673b1906460ecf1c307

BUG= chromium-os:9180
TEST= ran vmstat & hdparm to see when the last read/write to the disk
happened and when the drive transitioned to standby state.  With this
change in place, on battery the hard drive transitioned to standby
state 5 seconds after the last read/write.

Review URL: http://codereview.chromium.org/5032002
1 file changed