staging: dwc2: Make dwc2_set_uninitialized more specific
Before, it was a function that would set all members of a given struct
containing only int members to -1. Now, it is renamed to
dwc_set_all_params and it works only on the dwc2_core_params struct.
This makes sure that all of the slightly dubious casting and assumptions
happen inside the function instead of by the caller.