gcr: add libgcrypt dependency

* otherwise it tries to use libraries from wrong sysroot or sometimes
  it fails in do_configure already with:
  | configure.ac:160: warning: macro 'AM_PATH_LIBGCRYPT' not found in   library
  | autoreconf: running:   /OE/build/oe-core/tmp-eglibc/sysroots/x86_64-linux/usr/bin/autoconf   --force
  | configure.ac:160: error: possibly undefined macro: AM_PATH_LIBGCRYPT

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>