cpufreq: interactive: set at least hispeed when above hispeed load

If load is above go_hispeed_load, always go to at least hispeed_freq,
even when reducing speed from a higher speed, not just when jumping
up from minimum speed.  Avoids running at a lower than intended
speed after a burst of even higher load.

Change-Id: I5b9d2a15ba25ce609b21bac7c724265cf6838dee
Signed-off-by: Todd Poynor <toddpoynor@google.com>