agent: Add support for TPM2 for ECC KEM.
* agent/agent.h (agent_tpm2d_ecc_kem): New. * agent/divert-tpm2.c (agent_tpm2d_ecc_kem): New. * agent/pkdecrypt.c (ecc_pgp_kem_decap): Call agent_tpm2d_ecc_kem.
- GnuPG-bug-id: T7649
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>