ABA Bank does this. They are fairly ubiquitous locally and have a number of branches in Phnom Penh. I opened an account with them in 2013 as a foreigner. They required my passport, proof of accommodation (my hotel booking was fine) and my visitor visa (I believe it was 3 months).
If I remember correctly, you can choose between a free ATM card and a non-free Mastercard. I believe the Mastercard is ~25 USD a year and works overseas. The ATM one only works locally. They have internet banking that is functional (but not really pretty) and works from overseas. They have a token generator (that they call a "machine") that you can use to access your internet banking from anywhere in the world.
Do note that they do NOT ship card / token generator replacements outside of Cambodia and you'll need to go back to the branch to get your card.