[POWERPC] Create a "wrapper" script and use it in arch/powerpc/boot

This puts the knowledge of how to create various sorts of zImage
wrappers into a script called "wrapper" that could be used outside of
the kernel tree.  This changes arch/powerpc/boot so it first builds
the files that the wrapper script needs, then runs it to create
whatever flavours of zImage are required.

This version does uImages as well.  The zImage names are changed
slightly; zImage.pseries is the one with the PT_NOTE program header
entry added, and zImage.pmac is the one without.  If the
zImage.pseries gets made, it will also get hardlinked to zImage;
otherwise, if zImage.pmac is made, it gets hardlinked to zImage.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 01667d1..a00fe72 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -20,6 +20,7 @@
 CROSS32CC		:= $(CROSS32_COMPILE)gcc
 CROSS32AS		:= $(CROSS32_COMPILE)as
 CROSS32LD		:= $(CROSS32_COMPILE)ld
+CROSS32AR		:= $(CROSS32_COMPILE)ar
 CROSS32OBJCOPY		:= $(CROSS32_COMPILE)objcopy
 
 ifeq ($(HAS_BIARCH),y)
@@ -28,10 +29,11 @@
 CROSS32AS	:= $(AS) -a32
 CROSS32LD	:= $(LD) -m elf32ppc
 CROSS32OBJCOPY	:= $(OBJCOPY)
+CROSS32AR	:= $(AR)
 endif
 endif
 
-export CROSS32CC CROSS32AS CROSS32LD CROSS32OBJCOPY
+export CROSS32CC CROSS32AS CROSS32LD CROSS32AR CROSS32OBJCOPY
 
 KBUILD_DEFCONFIG := $(shell uname -m)_defconfig
 
@@ -146,7 +148,7 @@
 
 CPPFLAGS_vmlinux.lds	:= -Upowerpc
 
-BOOT_TARGETS = zImage zImage.initrd znetboot znetboot.initrd vmlinux.sm uImage vmlinux.bin
+BOOT_TARGETS = zImage zImage.initrd uImage
 
 PHONY += $(BOOT_TARGETS)