tpm2: unify symbolic name infra for PCRs

tpm2: unify symbolic name infra for PCRs

We so far maintained two places for symboic names for PCRs. One in
tpm2-util.h and one in tpm-pcr.h.

Let's unify this into one, i.e. move the full list from tpm2-util.h into
tpm-pcr.h, replacing the short list placed so far there.

Systematically prefix the definitions with TPM2_ or tpm2_, to follow how
we do this for all other defines in this context.

No change in behaviour, just unification of tables.