package/pipewire: remove optional dependency to vulkan

Fixes:
http://autobuild.buildroot.net/results/8b4/8b4d12de72a1407e74bd9b9b79f4e01ae86510ba/

vulkan.pc is provided by the package vulkan-loader which is not
part of buildroot yet.

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

package/pipewire/pipewire.mk

@@ -30,6 +30,7 @@ PIPEWIRE_CONF_OPTS += \
 	-Dvideoconvert=enabled \
 	-Dvideotestsrc=enabled \
 	-Dvolume=enabled \
+	-Dvulkan=disabled \
 	-Dsession-managers=[] \
 	-Dlegacy-rtkit=false \
 	-Davb=disabled \
@@ -180,12 +181,6 @@ else
 PIPEWIRE_CONF_OPTS += -Dlibusb=disabled
 endif
 
-ifeq ($(BR2_PACKAGE_MESA3D_VULKAN_DRIVER),y)
-PIPEWIRE_CONF_OPTS += -Dvulkan=enabled
-PIPEWIRE_DEPENDENCIES += mesa3d
-else
-PIPEWIRE_CONF_OPTS += -Dvulkan=disabled
-endif
 
 ifeq ($(BR2_PACKAGE_LIBSNDFILE),y)
 PIPEWIRE_CONF_OPTS += -Dpw-cat=enabled -Dsndfile=enabled