MIPS: Introduce arch/mips/Kbuild

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
To: linux-mips <linux-mips@linux-mips.org>
To: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1300/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kbuild

+# mips object files
+# The object files are linked as core-y files would be linked
+
+obj-y += kernel/
+obj-y += mm/
+obj-y += math-emu/

arch/mips/Makefile

@@ -706,7 +706,8 @@ head-y := arch/mips/kernel/head.o arch/mips/kernel/init_task.o
 
 libs-y			+= arch/mips/lib/
 
-core-y			+= arch/mips/kernel/ arch/mips/mm/ arch/mips/math-emu/
+# See arch/mips/Kbuild for content of core part of the kernel
+core-y += arch/mips/
 
 drivers-$(CONFIG_OPROFILE)	+= arch/mips/oprofile/