scd: ccid-driver improvement

[NIIBE Yutaka]

I applied the patch to both branches (STABLE-BRANCH-2-0 and master).

Now, users of internal CCID driver can enjoy the following change of
GnuPG, finally.

    commit ab4ea45f54006eba55db11263431c4c0c4f557dc
    Author: Werner Koch <wk at gnupg.org>
    Date:   Tue Nov 6 14:39:22 2012 +0100

        Allow decryption with card keys > 3072 bit
--