MIPS: Refactor arch/mips/boot/Makefile

- remove stuff that is not needed
  VMLINUX assignment, all: rule
- use hostprogs-y for the host program
- use kbuild rules for the three targets - to beautify output
- drop clean-files - it is no longer needed
- simplify arch/mips/Makefile when calling targets in boot/Makefile

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/1303/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 50f780a..93ce1ce 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -266,7 +266,6 @@
 vmlinux.64: vmlinux
 	$(OBJCOPY) -O $(64bit-bfd) $(OBJCOPYFLAGS) $< $@
 
-makeboot =$(Q)$(MAKE) $(build)=arch/mips/boot VMLINUX=$(vmlinux-32) $(1)
 makezboot =$(Q)$(MAKE) $(build)=arch/mips/boot/compressed \
 	   VMLINUX_LOAD_ADDRESS=$(load-y) 32bit-bfd=$(32bit-bfd) $(1)
 
@@ -284,14 +283,8 @@
 vmlinuz.srec: vmlinux
 	+@$(call makezboot,$@)
 
-vmlinux.bin: $(vmlinux-32)
-	+@$(call makeboot,$@)
-
-vmlinux.ecoff: $(vmlinux-32)
-	+@$(call makeboot,$@)
-
-vmlinux.srec: $(vmlinux-32)
-	+@$(call makeboot,$@)
+vmlinux.bin vmlinux.ecoff vmlinux.srec: $(vmlinux-32) FORCE
+	$(Q)$(MAKE) $(build)=arch/mips/boot VMLINUX=$(vmlinux-32) arch/mips/boot/$@
 
 CLEAN_FILES += vmlinux.ecoff \
 	       vmlinux.srec