kbuild: use relative path more to include Makefile

Prior to this commit, it was impossible to use relative path to
include Makefiles from the top level Makefile because the option
"--include-dir=$(srctree)" becomes effective when Make enters into
sub Makefiles.

To use relative path in any places, this commit moves the option
above the "sub-make" target.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 8f57fc7..d152dfb 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -225,7 +225,7 @@
 #
 # Board-dependent options and extra files
 #
-include $(srctree)/arch/mips/Kbuild.platforms
+include arch/mips/Kbuild.platforms
 
 ifdef CONFIG_PHYSICAL_START
 load-y					= $(CONFIG_PHYSICAL_START)
diff --git a/arch/um/Makefile b/arch/um/Makefile
index e4b1a96..17d4460 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -43,8 +43,8 @@
 
 HOST_DIR := arch/$(HEADER_ARCH)
 
-include $(srctree)/$(ARCH_DIR)/Makefile-skas
-include $(srctree)/$(HOST_DIR)/Makefile.um
+include $(ARCH_DIR)/Makefile-skas
+include $(HOST_DIR)/Makefile.um
 
 core-y += $(HOST_DIR)/um/
 
@@ -73,7 +73,7 @@
 	$(filter -I%,$(CFLAGS)) -D_FILE_OFFSET_BITS=64 -idirafter include
 
 #This will adjust *FLAGS accordingly to the platform.
-include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
+include $(ARCH_DIR)/Makefile-os-$(OS)
 
 KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/include \
 		   -I$(srctree)/$(HOST_DIR)/include/uapi \
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 5ba2d9c..2fda005 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -63,7 +63,7 @@
 				$(call cc-option,-fno-unit-at-a-time))
 
         # CPU-specific tuning. Anything which can be shared with UML should go here.
-        include $(srctree)/arch/x86/Makefile_32.cpu
+        include arch/x86/Makefile_32.cpu
         KBUILD_CFLAGS += $(cflags-y)
 
         # temporary until string.h is fixed
diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um
index 95eba55..5b7e898 100644
--- a/arch/x86/Makefile.um
+++ b/arch/x86/Makefile.um
@@ -18,7 +18,7 @@
 export LDS_EXTRA
 
 # First of all, tune CFLAGS for the specific CPU. This actually sets cflags-y.
-include $(srctree)/arch/x86/Makefile_32.cpu
+include arch/x86/Makefile_32.cpu
 
 # prevent gcc from keeping the stack 16 byte aligned. Taken from i386.
 cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)