Video Common: Fix Speed Counter Sample Size

[Sam-Belliveau]

A typo in the original commit made the speed counter sample the last 6 seconds (because of some smoothing it ends up being more like 10 seconds)

This commit reverts it back to its original 0.5s

[Pokechu22]

This definitely improves things, but I feel like it would make more sense to use the value given by "performance sample window" instead of hardcoding a specific value for the speed counter, so that all 3 counters are in sync. If that would be difficult to implement, this is good enough, though.

[Sam-Belliveau]

This definitely improves things, but I feel like it would make more sense to use the value given by "performance sample window" instead of hardcoding a specific value for the speed counter, so that all 3 counters are in sync. If that would be difficult to implement, this is good enough, though.

it would be easy to implement, but the emulation speed counter is meant to be used by internal aspects of dolphin (like ideally the sound in the future) and was made so that the performance sample window wouldnt affect things like sound.

[Pokechu22]

OK, that's probably fine then. Perhaps it could be changed so that the performance window affects the UI version only and not the one used internally, but I don't think that needs to be done now.