nic/Makefile: trivial Makefile and empty files.

The empty files in here are the way I had split the nic driver, the
Makefile is a standard thing for modules. Depends on $LINUX being set

nic/Makefile

+
+obj-m := wr-nic.o
+wr-nic-objs := module.o device.o nic-core.o endpoint.o ethtool.o \
+		pps.o timestamp.o dmtd.o
+
+# Try to force a -I from ../wr-headers. Note that this is re-run from $LINUX
+WR_NIC_DIR ?= $(shell /bin/pwd)
+export WR_NIC_DIR
+EXTRA_CFLAGS := -I$(WR_NIC_DIR)/../wr-headers
+
+# What follows is standard stuff
+export ARCH ?= arm
+export CROSS_COMPILE ?= $(CROSS_COMPILE_ARM)
+
+all modules:
+	$(MAKE) CONFIG_DEBUG_SECTION_MISMATCH=y \
+		-C $(LINUX) SUBDIRS=$(shell /bin/pwd) modules
+
+# We might "$(MAKE) -C $(LINUX)" but "make clean" with no LINUX defined
+# is sometimes useful to have
+clean:
+	rm -f *.mod.c *.o *.ko .*cmd Module.symvers modules.order *~
+	rm -rf .tmp_versions