Add Keymaster 4.1

Note that CL is missing complete tests (what's included is just a
stub, really) and support library code.  All of that will come in
near-future CLs.  This CL omits them because they'll take time and
there's a need to unblock Keymaster 4.1 implementers now.

Bug: 140193672
Bug: 140192237
Bug: 140824829
Test: Will be in a future CL
Change-Id: I0e6e3a38356f0517158a10604b549415641ad1b9