package/opensc: disable cmocka

Disable cmocka (enabled by default) to avoid the following uclibc build
failure raised since the addition of the package in commit
8aaa7ecbce1d10cbcd880c3da5e429988f96176a:

In file included from p11test_common.h:30,
                 from p11test_helpers.h:25,
                 from p11test.c:24:
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/powerpc-buildroot-linux-uclibc/sysroot/usr/include/cmocka.h:2334:47: error: unknown type name 'va_list'
 2334 | void vprint_message(const char* const format, va_list args) CMOCKA_PRINTF_ATTRIBUTE(1, 0);
      |                                               ^~~~~~~

Fixes:
 - http://autobuild.buildroot.org/results/19d1171a76cd4789472b16aa24b44f58cd7e0a1e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/opensc/opensc.mk

@@ -11,6 +11,6 @@ OPENSC_LICENSE_FILES = COPYING
 OPENSC_CPE_ID_VENDOR = opensc_project
 OPENSC_DEPENDENCIES = openssl pcsc-lite
 OPENSC_INSTALL_STAGING = YES
-OPENSC_CONF_OPTS = --disable-strict
+OPENSC_CONF_OPTS = --disable-cmocka --disable-strict
 
 $(eval $(autotools-package))