2.4.21-rc1 doesn't build on ppc (6xx/pmac)

2.4.21-pre7 built and ran Ok on my PowerMac 4400 with
CONFIG_6xx=y and CONFIG_ALL_PPC=y.
2.4.21-rc1 fails at the end of the build with:

ld -T arch/ppc/vmlinux.lds -Ttext 0xc0000000 -Bstatic arch/ppc/kernel/head.o arch/ppc/kernel/idle_6xx.o init/main.o init/version.o init/do_mounts.o \
	--start-group \
	arch/ppc/kernel/kernel.o arch/ppc/platforms/platform.o arch/ppc/mm/mm.o arch/ppc/lib/lib.o kernel/kernel.o mm/mm.o fs/fs.o ipc/ipc.o \
	 drivers/char/char.o drivers/block/block.o drivers/misc/misc.o drivers/net/net.o drivers/ide/idedriver.o drivers/cdrom/driver.o drivers/pci/driver.o drivers/macintosh/macintosh.o drivers/video/video.o drivers/usb/usbdrv.o drivers/media/media.o drivers/input/inputdrv.o \
	net/network.o \
	/tmp/linux-2.4.21-rc1/lib/lib.a \
	--end-group \
	-o vmlinux
arch/ppc/kernel/head.o(__ftr_fixup+0x60): undefined reference to `CPU_FTR_HAS_HIGH_BATS'
arch/ppc/kernel/head.o(__ftr_fixup+0x64): undefined reference to `CPU_FTR_HAS_HIGH_BATS'
arch/ppc/kernel/kernel.o: In function `sys_call_table':
arch/ppc/kernel/kernel.o(.data+0x330c): undefined reference to `__setup_cpu_7450'
arch/ppc/kernel/kernel.o(.data+0x332c): undefined reference to `__setup_cpu_7450'
arch/ppc/kernel/kernel.o(.data+0x334c): undefined reference to `__setup_cpu_7450'
arch/ppc/kernel/kernel.o(.data+0x336c): undefined reference to `__setup_cpu_7455'
arch/ppc/kernel/kernel.o(.data+0x338c): undefined reference to `__setup_cpu_7455'
arch/ppc/kernel/kernel.o(.data+0x33ac): undefined reference to `__setup_cpu_7455'
make: *** [vmlinux] Error 1

/Mikael