Let's define the voltatile registers (those that can't be cached) and
enable caching. The rk808 is accessed almost constantly with cpufreq
so this is really nice.
As measured by ftrace:
before this change: cpu0_set_target() => ~2200us
after this change: cpu0_set_target() => ~500us
Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Chris Zhong <zyw@rock-chips.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>