blackfin: convert makefiles to Kbuild style

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Sonic Zhang <sonic.zhang@analog.com>
diff --git a/arch/blackfin/lib/Makefile b/arch/blackfin/lib/Makefile
index 5603eb9..a5c552f 100644
--- a/arch/blackfin/lib/Makefile
+++ b/arch/blackfin/lib/Makefile
@@ -9,41 +9,21 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-include $(TOPDIR)/config.mk
-
 CFLAGS += -DBFIN_BOARD_NAME='"$(BOARD)"'
 
-LIB	= $(obj)lib$(ARCH).o
-
-SOBJS-y	+= ins.o
-SOBJS-y	+= memcmp.o
-SOBJS-y	+= memcpy.o
-SOBJS-y	+= memmove.o
-SOBJS-y	+= memset.o
-SOBJS-y	+= outs.o
-SOBJS-$(CONFIG_CMD_KGDB) += __kgdb.o
-
-COBJS-y	+= board.o
-COBJS-y	+= boot.o
-COBJS-y	+= cache.o
-COBJS-y	+= clocks.o
-COBJS-$(CONFIG_CMD_CACHE_DUMP) += cmd_cache_dump.o
-COBJS-$(CONFIG_CMD_KGDB) += kgdb.o
-COBJS-y	+= muldi3.o
-COBJS-$(CONFIG_HAS_POST) += post.o
-COBJS-y	+= string.o
-
-SRCS	:= $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
-OBJS	:= $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))
-
-$(LIB):	$(obj).depend $(OBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-# defines $(obj).depend target
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################
+obj-y	+= ins.o
+obj-y	+= memcmp.o
+obj-y	+= memcpy.o
+obj-y	+= memmove.o
+obj-y	+= memset.o
+obj-y	+= outs.o
+obj-$(CONFIG_CMD_KGDB) += __kgdb.o
+obj-y	+= board.o
+obj-y	+= boot.o
+obj-y	+= cache.o
+obj-y	+= clocks.o
+obj-$(CONFIG_CMD_CACHE_DUMP) += cmd_cache_dump.o
+obj-$(CONFIG_CMD_KGDB) += kgdb.o
+obj-y	+= muldi3.o
+obj-$(CONFIG_HAS_POST) += post.o
+obj-y	+= string.o