Re: How do I specify the GPIO lines attributes in the bsp.hconfig" file?
Option1. Create it in MHC, then look at the generated files to see the generated init code, copy code to your BSP.
Option2. Create an empty starter project for the board with all hardware init, including pins. Copy that for each new project on board. This "simple" project can be the same one you use to validate your hardware, or "factory test" your hardware.
Option3. When you got a new project for same board, copy working project and delete unnecessary code & MHC settings.