As long as your Charger & Cable can supply the necessary 2.1A you'll be good to go
USB 2.0 will also work fine as long as it can supply 2.1A to the S5 - anything lesser will provide slower charging - no charging depending...
Thanks for the reply
It's dubious the only original Samsung chargers I found for the S5 are 5.0V 2A ones, while the one that comes with the phone is 5.3v 2A...