Enable feature API backend

Packages describing “fapi” as local USE flag

Package “fapi” Flag Description
app-crypt/tpm2-pkcs11 Enable feature API backend
app-crypt/tpm2-tss Enable feature API (requires openssl as crypto backend)
dev-python/tpm2-pytss Enable feature API (requires tpm2-tss be compile with thes same)
app-crypt/tpm2-tools Enable feature API tools

All packages providing a “fapi” USE flag (1)