scd: Remove unused files.

* scd/Makefile.am (sc_copykeys_*): Remove.
* scd/sc-copykeys.c: Remove.
* scd/pcsc-wrapper.c: Remove.
* scd/{card-common.h,card-dinsig.c,card-p15.c,card.c}: Remove.

sc-copykeys doesn't work any more because it's based on old API.
pcsc-wrapper has gone because of nPth which is compatible to pthreads.
The card* files are old files, now we have app*.