Install headers into linux-headers package

Change-Id: I9953a1ca1e56c50c6211d20435167c842b699331

debian/rules

diff --git a/debian/rules b/debian/rules
index afc2ffe..e314154 100755
--- a/debian/rules
+++ b/debian/rules
@@ -44,3 +44,23 @@
 
 	install -d $(DESTDIR)/boot
 	install -p -m 655 boot.img $(DESTDIR)/boot
+
+	install -d $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)
+	install -d $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)/arch/arm
+	install -d $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)/arch/$(ARCH)/kernel
+
+	cp -a .config $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)
+	cp -a Module.symvers $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)
+	cp -a include $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)
+	cp -a arch/$(ARCH)/include $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)/arch/$(ARCH)
+	cp -a arch/arm/include $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)/arch/arm
+	cp -a Makefile $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)
+
+	( \
+		find arch/$(ARCH) -maxdepth 1 -name 'Makefile*' -print; \
+		find arch/$(ARCH) \( -name 'module.lds' -o -name 'Kbuild.platforms' -o -name 'Platform' \) -print; \
+		find $$(find arch/$(ARCH) \( -name include -o -name scripts \) -type d -print) -print; \
+	) | cpio -pdm $(DESTDIR_HEADERS)/usr/src/linux-headers-$(VERSION)
+
+	install -d $(DESTDIR_HEADERS)/lib/modules/$(VERSION)
+	ln -s /usr/src/linux-headers-$(VERSION) $(DESTDIR_HEADERS)/lib/modules/$(VERSION)/build