microblaze: move core-y in arch/microblaze/Makefile to arch/microblaze/Kbuild

Use obj-y to clean up Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210811164518.187497-1-masahiroy@kernel.orgSigned-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/Kbuild

 # SPDX-License-Identifier: GPL-2.0-only
+obj-y			+= kernel/
+obj-y			+= mm/
+obj-$(CONFIG_PCI)	+= pci/
+obj-y			+= boot/dts/

arch/microblaze/Makefile

@@ -50,17 +50,12 @@ KBUILD_CFLAGS += -ffixed-r31 $(CPUFLAGS-y) $(CPUFLAGS-1) $(CPUFLAGS-2)
 
 head-y := arch/microblaze/kernel/head.o
 libs-y += arch/microblaze/lib/
-core-y += arch/microblaze/kernel/
-core-y += arch/microblaze/mm/
-core-$(CONFIG_PCI) += arch/microblaze/pci/
 
 boot := arch/microblaze/boot
 
 # Are we making a simpleImage.<boardname> target? If so, crack out the boardname
 DTB:=$(subst simpleImage.,,$(filter simpleImage.%, $(MAKECMDGOALS)))
 
-core-y	+= $(boot)/dts/
-
 export DTB
 
 all: linux.bin