package/mesa3d-demos: add dependency on libdecor for wayland support

libdecor cannot be selected due to a circular dependency:

package/wayland/Config.in:1:error: recursive dependency detected!
package/wayland/Config.in:1: symbol BR2_PACKAGE_WAYLAND is selected by BR2_PACKAGE_LIBDECOR
package/libdecor/Config.in:1: symbol BR2_PACKAGE_LIBDECOR is selected by BR2_PACKAGE_MESA3D_DEMOS
package/mesa3d-demos/Config.in:1: symbol BR2_PACKAGE_MESA3D_DEMOS is selected by BR2_PACKAGE_PIGLIT
package/piglit/Config.in:1: symbol BR2_PACKAGE_PIGLIT depends on BR2_PACKAGE_WAFFLE_SUPPORTS_WAYLAND
package/waffle/Config.in:7: symbol BR2_PACKAGE_WAFFLE_SUPPORTS_WAYLAND depends on BR2_PACKAGE_WAYLAND

Without libdecor, the build fails since the bump of mesa3d-demos to
version 9.0.0 in 80304d9911f34f8a0173a4f37d52f93177478cc7:

"""
Run-time dependency libdecor-0 found: NO (tried pkgconfig and cmake)
Looking for a fallback subproject for the dependency libdecor-0
../output-1/build/mesa3d-demos-9.0.0/meson.build:88:17: ERROR: Automatic wrap-based subproject downloading is disabled
"""

Fixes:

  http://autobuild.buildroot.net/results/8de50be8233f0133aadc26bda71b48d7ec329e04/

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/mesa3d-demos/mesa3d-demos.mk

@@ -62,8 +62,8 @@ else
 MESA3D_DEMOS_CONF_OPTS += -Dosmesa=disabled
 endif
 
-ifeq ($(BR2_PACKAGE_WAYLAND),y)
-MESA3D_DEMOS_DEPENDENCIES += libxkbcommon wayland
+ifeq ($(BR2_PACKAGE_LIBDECOR)$(BR2_PACKAGE_WAYLAND),yy)
+MESA3D_DEMOS_DEPENDENCIES += libdecor libxkbcommon wayland
 MESA3D_DEMOS_CONF_OPTS += -Dwayland=enabled
 else
 MESA3D_DEMOS_CONF_OPTS += -Dwayland=disabled