Remove DmxNode*Type.mk makefiles

Delete firmware-template/DmxNodeNodeType.mk and firmware-template/DmxNodeOutputType.mk. These files contained conditional Makefile logic that set EXTRA_INCLUDES based on MAKE_FLAGS/DEFINES for various DMX node and output types (ARTNET, E131 and multiple OUTPUT_DMX_* variants). Removing these template fragments cleans up the firmware-template; update include handling elsewhere if this functionality is still required.

Author: vanvught