libwebsockets: enable built in uloop support

uloop is always available on OpenWrt, so build in LWS's uloop support by
default. Size difference of .ipk is 683 bytes, or about 0.5%.
No known applications use this at present, but it seems better to
proactively offer it.

Signed-off-by: Karl Palsson <karlp@etactica.com>

libs/libwebsockets/Makefile

@@ -29,6 +29,7 @@ include $(INCLUDE_DIR)/cmake.mk
 CMAKE_OPTIONS += -DLWS_IPV6=$(if $(CONFIG_IPV6),ON,OFF)
 CMAKE_OPTIONS += -DISABLE_WERROR=ON
 CMAKE_OPTIONS += -DCMAKE_BUILD_TYPE=Release
+CMAKE_OPTIONS += -DLWS_WITH_ULOOP=ON
 
 # turn off all test apps
 CMAKE_OPTIONS += -DLWS_WITHOUT_TESTAPPS=ON