scd:nks: Support READKEY with keygrip and for "NKS-IDLM" keyref.
* scd/app-nks.c (do_readkey): Allow KEYGRIP access. Support NKS-IDLM.XXXX keyref.
(cherry picked from commit 3b392630881350baabeba16fa760bad04be94d03)
- GnuPG-bug-id: T5150
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>