Add option GPU_PHYSICS

[pchakraborty]

Added cmake option GPU_PHYSICS with a default value of OFF. If ON, find OpenACC.

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[pchakraborty]

Would the option GPU_PHYSICS qualify as a significant change? I believe so, but wanted to check before updating CHANGELOG.

[mathomp4]

Would the option GPU_PHYSICS qualify as a significant change? I believe so, but wanted to check before updating CHANGELOG.

@pchakraborty Yeah, I think so. Can you add a changelog entry and then I'll merge in?

[pchakraborty]

@mathomp4 Is this what you meant here? I’m not ready to have this merged it, just wanted to run it by you.

[mathomp4]

@mathomp4 Is this what you meant here? I’m not ready to have this merged it, just wanted to run it by you.

@pchakraborty I think so, yes! Just in case we have another compiler at some point with these options :)