Add binder and ashmem kernel drivers as out-of-tree modules

Based on code from https://github.com/hungys/binder-for-linux

kernel/ashmem/Makefile

@@ -0,0 +1,19 @@
+ccflags-y += -I$(src) -Wno-error=implicit-int
+
+ifneq ($(KERNELRELEASE),)
+obj-m := ashmem_linux.o
+ashmem_linux-y := deps.o ashmem.o
+
+$(obj)/deps.o: $(src)/deps.h
+
+$(obj)/deps.h: $(src)/gen_deps.sh
+	sudo $(src)/gen_deps.sh > $@
+else
+KERNEL_SRC ?= /lib/modules/$(shell uname -r)/build
+
+all:
+	$(MAKE) -C $(KERNEL_SRC) V=0 M=$$PWD
+
+clean:
+	rm -rf deps.h *.o *.ko *.mod.c *.symvers *.order .*.cmd .tmp_versions
+endif