crda: move libnl, libgcrypt to DEPENDS

crda has a build time dependence on libgcrypt, so move the dependence
from RDEPENDS to DEPENDS.

Otherwise the build fails with:

reglib.c:28:20: fatal error: gcrypt.h: No such file or directory

Signed-off-by: Javier Viguera <javier.viguera@digi.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>