meson: reconfigure on incremental builds

When toggling a package specific config knob, we need to pass --reconfigure
to the meson setup command if an earlier build already exists.

Fixes #15032.

Signed-off-by: Andre Heider <a.heider@gmail.com>

devel/meson/meson.mk

@@ -97,6 +97,7 @@ endef
 define Host/Configure/Meson
 	$(call Meson/CreateNativeFile,$(HOST_BUILD_DIR)/openwrt-native.txt)
 	$(call Meson, \
+		setup $(if $(wildcard $(MESON_HOST_BUILD_DIR)/meson-*),--reconfigure,) \
 		--native-file $(HOST_BUILD_DIR)/openwrt-native.txt \
 		$(MESON_HOST_ARGS) \
 		$(MESON_HOST_BUILD_DIR) \
@@ -120,6 +121,7 @@ define Build/Configure/Meson
 	$(call Meson/CreateNativeFile,$(PKG_BUILD_DIR)/openwrt-native.txt)
 	$(call Meson/CreateCrossFile,$(PKG_BUILD_DIR)/openwrt-cross.txt)
 	$(call Meson, \
+		setup $(if $(wildcard $(MESON_BUILD_DIR)/meson-*),--reconfigure,) \
 		--buildtype plain \
 		--native-file $(PKG_BUILD_DIR)/openwrt-native.txt \
 		--cross-file $(PKG_BUILD_DIR)/openwrt-cross.txt \