A solar array consists mainly of solar cells, a supporting structure and an electric harness.
The mass of the solar cells and their efficiency can be found in datasheets online; look for example for the azurspace website. Multiplying the efficiency with the incoming solar flux on Mars surface, will give you the power per square meter of solar cell generated. There are some additional losses in the power system and due to thermal effects, but this will give you a good first estimate.
So: P[W/m^2]=efficiency * mars flux [W/m^2]
The solar cells need to be supported. In satellites this currently is done with honeycomb panels. However for your Mars base you might want a specific design. It's probably best if you make an initial structure, and estimate the mass of that structure (per unit area).
If the mass of the electrical harness is ignored you can calculate the mass of a square meter of cells, and add that to the mass of a square meter of your structure.
Based on Nathan Tuggy's comment, let me clarify some things. I might have misunderstood the question. I don't think it's possible to get the area from the specific power (per unit mass) alone. You would indeed need to know the mass per area of the panels in order to get the specific power per unit area.
The specific power should be given within some context to be useful. Power generated is dependent on incoming flux, efficiency and temperature as well.