kbuild: ia64 use generic asm-offsets.h support

Delete obsolete stuff from arch Makefile
Rename file to asm-offsets.h
The trick used in the arch Makefile to circumvent the circular
dependency is kept.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index f9bd88a..7ed678c 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -82,25 +82,18 @@
 archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)
 
-CLEAN_FILES += include/asm-ia64/.offsets.h.stamp vmlinux.gz bootloader
-
-MRPROPER_FILES += include/asm-ia64/offsets.h
-
-prepare: include/asm-ia64/offsets.h
-
-arch/ia64/kernel/asm-offsets.s: include/asm include/linux/version.h include/config/MARKER
-
-include/asm-ia64/offsets.h: arch/ia64/kernel/asm-offsets.s
-	$(call filechk,gen-asm-offsets)
-
-arch/ia64/kernel/asm-offsets.s: include/asm-ia64/.offsets.h.stamp
+prepare:  include/asm-ia64/.offsets.h.stamp
 
 include/asm-ia64/.offsets.h.stamp:
 	mkdir -p include/asm-ia64
-	[ -s include/asm-ia64/offsets.h ] \
-	 || echo "#define IA64_TASK_SIZE 0" > include/asm-ia64/offsets.h
+	[ -s include/asm-ia64/asm-offsets.h ] \
+	|| echo "#define IA64_TASK_SIZE 0" > include/asm-ia64/asm-offsets.h
 	touch $@
 
+
+
+CLEAN_FILES += vmlinux.gz bootloader include/asm-ia64/.offsets.h.stamp
+
 boot:	lib/lib.a vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $@