minizip: disable compatibility headers

minizip enables zip.h and unzip.h compatibility headers since version
2.7.2 and
https://github.com/nmoinvaz/minizip/commit/1b2b32c8b8c7ea441b14a2fd827d7e2dc886776c

This is an issue as php fails to build if minizip is built after libzip
because minizip installs a zip.h header without zip_stat, ZIP_CREATE,
ZIP_FL_NOCASE, zip_fopen, etc ...

So until the compatibility headers are enhanced/fixed in minizip, disable them

Fixes:
 - http://autobuild.buildroot.org/results/7b41f4e4a521b1e17aa885aac4419b26e0dd8700

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/minizip/minizip.mk

@@ -11,7 +11,9 @@ MINIZIP_DEPENDENCIES = \
 	$(if $(BR2_PACKAGE_LIBBSD),libbsd) \
 	$(if $(BR2_PACKAGE_LIBICONV),libiconv)
 MINIZIP_INSTALL_STAGING = YES
-MINIZIP_CONF_OPTS = $(if $(BR2_PACKAGE_MINIZIP_DEMOS),-DBUILD_TEST=ON)
+MINIZIP_CONF_OPTS = \
+	$(if $(BR2_PACKAGE_MINIZIP_DEMOS),-DBUILD_TEST=ON) \
+	-DUSE_COMPAT=OFF
 MINIZIP_LICENSE = Zlib
 MINIZIP_LICENSE_FILES = LICENSE