Only require RKP on T+ chipsets

It turns out we had a bug (b/263844771) in how RKP support was
detected, and that was fixed. However, due to this bug, some S chipests
shipped without RKP support which is now required by the tests.

This change drops the RKP requirement from S chipsets. There should be
no new S chipsets, so this effectively grandfathers in the previous
ones that were skipped by the RKP VTS tests.

T+ tests (both VTS and other suites) will verify that RKP support is
there, so there is no gap introduced by this change.

Bug: 297139913
Test: VtsAidlKeyMintTargetTest
Change-Id: I387e5f058ada698747aac103c1745682291f2d1c