arm, cris, mips, sparc, powerpc, um, xtensa: fix build with bash 4.0

Albin Tonnerre <albin.tonnerre@free-electrons.com> reported:

    Bash 4 filters out variables which contain a dot in them.
    This happends to be the case of CPPFLAGS_vmlinux.lds.
    This is rather unfortunate, as it now causes
    build failures when using SHELL=/bin/bash to compile,
    or when bash happens to be used by make (eg when it's /bin/sh)

Remove the common definition of CPPFLAGS_vmlinux.lds by
pushing relevant stuff to either Makefile.build or the
arch specific kernel/Makefile where we build the linker script.

This is also nice cleanup as we move the information out where
it is used.

Notes for the different architectures touched:

arm - we use an already exported symbol
cris - we use a config symbol aleady available
       [Not build tested]
mips - the jiffies complexity has moved to vmlinux.lds.S where we need it.
       Added a few variables to CPPFLAGS - they are only used by
       the linker script.
       [Not build tested]
powerpc - removed assignment that is not needed
          [not build tested]
sparc - simplified it using $(BITS)
um - introduced a few new exported variables to deal with this
xtensa - added options to CPP invocation
         [not build tested]

Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index c825b14..77f5021 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -627,16 +627,6 @@
 cflags-y			+= -I$(srctree)/arch/mips/include/asm/mach-generic
 drivers-$(CONFIG_PCI)		+= arch/mips/pci/
 
-ifdef CONFIG_32BIT
-ifdef CONFIG_CPU_LITTLE_ENDIAN
-JIFFIES			= jiffies_64
-else
-JIFFIES			= jiffies_64 + 4
-endif
-else
-JIFFIES			= jiffies_64
-endif
-
 #
 # Automatically detect the build format. By default we choose
 # the elf format according to the load address.
@@ -660,8 +650,9 @@
 endif
 
 KBUILD_AFLAGS	+= $(cflags-y)
-KBUILD_CFLAGS	+= $(cflags-y) \
-			-D"VMLINUX_LOAD_ADDRESS=$(load-y)"
+KBUILD_CFLAGS	+= $(cflags-y)
+KBUILD_CPPFLAGS += -D"VMLINUX_LOAD_ADDRESS=$(load-y)"
+KBUILD_CPPFLAGS += -D"DATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)"
 
 LDFLAGS			+= -m $(ld-emul)
 
@@ -676,18 +667,6 @@
 
 OBJCOPYFLAGS		+= --remove-section=.reginfo
 
-#
-# Choosing incompatible machines durings configuration will result in
-# error messages during linking.  Select a default linkscript if
-# none has been choosen above.
-#
-
-CPPFLAGS_vmlinux.lds := \
-	$(KBUILD_CFLAGS) \
-	-D"LOADADDR=$(load-y)" \
-	-D"JIFFIES=$(JIFFIES)" \
-	-D"DATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)"
-
 head-y := arch/mips/kernel/head.o arch/mips/kernel/init_task.o
 
 libs-y			+= arch/mips/lib/