scudo: Remove positional template arguments for secondary cache. NFCI.

Make these arguments named constants in the Config class instead
of being positional arguments to MapAllocatorCache. This makes the
configuration easier to follow.

Eventually we should follow suit with the other classes but this is
a start.

Differential Revision:

GitOrigin-RevId: f21f3339ba315f181e195f368f2a7ecff1cee597
5 files changed