package/opensc: add zlib optional dependency

zlib is an optional dependency dependency (enabled by default) since the
addition of the package in commit
8aaa7ecbce1d10cbcd880c3da5e429988f96176a

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>
(cherry picked from commit 05f5e5b6f8e8363043b6136e9d622023ccf9eb52)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/opensc/opensc.mk

@@ -20,4 +20,11 @@ else
 OPENSC_CONF_OPTS += --disable-openssl
 endif
 
+ifeq ($(BR2_PACKAGE_ZLIB),y)
+OPENSC_DEPENDENCIES += zlib
+OPENSC_CONF_OPTS += --enable-zlib
+else
+OPENSC_CONF_OPTS += --disable-zlib
+endif
+
 $(eval $(autotools-package))