ARM: imx-common: convert makefiles to Kbuild style

Multiple targets are included in arch/arm/imx-common/Makefile
In order to refactor it,
we need to tweak Makefile and spl/Makefile.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

Makefile

@@ -416,6 +416,8 @@ ALL-y += $(obj)u-boot-nodtb-tegra.bin
 endif
 endif
 
+build := -f $(TOPDIR)/scripts/Makefile.build -C
+
 all:		$(ALL-y) $(SUBDIR_EXAMPLES)
 
 $(obj)u-boot.dtb:	checkdtc $(obj)u-boot
@@ -463,7 +465,7 @@ $(obj)u-boot.img:	$(obj)u-boot.bin
 		-d $< $@
 
 $(obj)u-boot.imx: $(obj)u-boot.bin depend
-		$(MAKE) -C $(SRCTREE)/arch/arm/imx-common $(OBJTREE)/u-boot.imx
+		$(MAKE) $(build) $(SRCTREE)/arch/arm/imx-common $(OBJTREE)/u-boot.imx
 
 $(obj)u-boot.kwb:       $(obj)u-boot.bin
 		$(obj)tools/mkimage -n $(CONFIG_SYS_KWD_CONFIG) -T kwbimage \
@@ -501,11 +503,11 @@ $(obj)tpl/u-boot-with-tpl.bin: $(obj)tpl/u-boot-tpl.bin $(obj)u-boot.bin
 		$(call SPL_PAD_APPEND,$<,$(obj)u-boot.bin,tpl/u-boot-tpl-pad.bin,$(CONFIG_TPL_PAD_TO))
 
 $(obj)u-boot-with-spl.imx: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin
-		$(MAKE) -C $(SRCTREE)/arch/arm/imx-common \
+		$(MAKE) $(build) $(SRCTREE)/arch/arm/imx-common \
 			$(OBJTREE)/u-boot-with-spl.imx
 
 $(obj)u-boot-with-nand-spl.imx: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin
-		$(MAKE) -C $(SRCTREE)/arch/arm/imx-common \
+		$(MAKE) $(build) $(SRCTREE)/arch/arm/imx-common \
 			$(OBJTREE)/u-boot-with-nand-spl.imx
 
 $(obj)u-boot.ubl:       $(obj)u-boot-with-spl.bin

arch/arm/imx-common/Makefile

@@ -7,31 +7,18 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-include $(TOPDIR)/config.mk
-
-LIB     = $(obj)libimx-common.o
-
 ifeq ($(SOC),$(filter $(SOC),mx25 mx35 mx5 mx6 vf610))
-COBJS-y	= iomux-v3.o
+obj-y	= iomux-v3.o
 endif
 ifeq ($(SOC),$(filter $(SOC),mx5 mx6))
-COBJS-y	+= timer.o cpu.o speed.o
-COBJS-$(CONFIG_SYS_I2C_MXC) += i2c-mxv7.o
+obj-y	+= timer.o cpu.o speed.o
+obj-$(CONFIG_SYS_I2C_MXC) += i2c-mxv7.o
 endif
 ifeq ($(SOC),$(filter $(SOC),mx6 mxs))
-COBJS-y	+= misc.o
+obj-y	+= misc.o
 endif
-COBJS-$(CONFIG_CMD_BMODE) += cmd_bmode.o
-COBJS-$(CONFIG_CMD_HDMIDETECT) += cmd_hdmidet.o
-COBJS	:= $(sort $(COBJS-y))
-
-SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
-
-all:	$(obj).depend $(LIB)
-
-$(LIB):	$(OBJS)
-	$(call cmd_link_o_target, $(OBJS))
+obj-$(CONFIG_CMD_BMODE) += cmd_bmode.o
+obj-$(CONFIG_CMD_HDMIDETECT) += cmd_hdmidet.o
 
 $(OBJTREE)/$(patsubst "%",%,$(CONFIG_IMX_CONFIG)).cfgtmp: $(OBJTREE)/%.cfgtmp : $(SRCTREE)/%
 	mkdir -p $(dir $@)
@@ -67,13 +54,3 @@ $(OBJTREE)/u-boot-with-nand-spl.imx: $(OBJTREE)/SPL $(OBJTREE)/u-boot.bin
 		$(OBJTREE)/u-boot.uim
 	cat $(OBJTREE)/spl/u-boot-nand-spl-pad.imx $(OBJTREE)/u-boot.uim > $@
 	rm $(OBJTREE)/spl/u-boot-nand-spl-pad.imx $(OBJTREE)/u-boot.uim
-
-
-#########################################################################
-
-# defines $(obj).depend target
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################

spl/Makefile

@@ -154,6 +154,8 @@ ifeq ($(wildcard $(LDSCRIPT)),)
 $(error could not find linker script)
 endif
 
+build := -f $(TOPDIR)/scripts/Makefile.build -C
+
 # Special flags for CPP when processing the linker script.
 # Pass the version down so we can handle backwards compatibility
 # on the fly.
@@ -173,7 +175,7 @@ $(OBJTREE)/MLO.byteswap: $(obj)u-boot-spl.bin
 		-a $(CONFIG_SPL_TEXT_BASE) -d $< $@
 
 $(OBJTREE)/SPL : $(obj)u-boot-spl.bin depend
-		$(MAKE) -C $(SRCTREE)/arch/arm/imx-common $@
+		$(MAKE) $(build) $(SRCTREE)/arch/arm/imx-common $@
 
 ALL-y	+= $(obj)$(SPL_BIN).bin