power: Allow global stats in power equations

Allow global stats such as sim_seconds in power equations to make it
possible to convert from event stats to rate stats.

Change-Id: I429abe0ffadc0dbd162eb39e0897143be472ef65
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2720
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
1 file changed