dgnc: Remove superfluous EXTRA_CFLAGS variable

Clean up Makefile by removing unnecessary definition of DG_NAME.
Signed-off-by: Cass May <cass@cassm.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgnc/Makefile

-EXTRA_CFLAGS += -DDG_NAME=\"dgnc-1.3-16\" -DDG_PART=\"40002369_F\"
+EXTRA_CFLAGS += -DDG_PART=\"40002369_F\"
 
 obj-$(CONFIG_DGNC) += dgnc.o