scd: Add reder information to --card-status.
* g10/call-agent.h, g10/call-agent.c (agent_release_card_info) g10/card-util.c (card_status): Add READER. * scd/apdu.c (close_ccid_reader, open_ccid_reader): Handle RDRNAME. (apdu_get_reader_name): New. * scd/ccid-driver.c (ccid_open_reader): Add argument to RDRNAME_P. * scd/command.c (cmd_learn): Return READER information.