package/doxygen: disable shared libs for host

doxygen fails to build with BUILD_SHARED_LIBS=ON as it only
for some targets honors this flag and links the rest static.
So enforce BUILD_SHARED_LIBS=OFF for this package.

Signed-off-by: Michael Nosthoff <buildroot@heine.tech>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/doxygen/doxygen.mk

@@ -11,4 +11,6 @@ DOXYGEN_LICENSE = GPL-2.0
 DOXYGEN_LICENSE_FILES = LICENSE
 HOST_DOXYGEN_DEPENDENCIES = host-flex host-bison
 
+HOST_DOXYGEN_CONF_OPTS += -DBUILD_SHARED_LIBS=OFF
+
 $(eval $(host-cmake-package))