Trying to build a PMC-Sierra MSP4200 VoIP gateway defconfig will not work
since MIPS34K_MISSED_ITLB_WAR is not defined for all boards supported
within pmc-serria/msp71xx. This patch defines MIPS34K_MISSED_ITLB_WAR to
prevent such build failures:

  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  SYMLINK include/asm -> include/asm-mips
  CC      arch/mips/kernel/asm-offsets.s
In file included fromlinux-msp71xx/linux-2.6.29/arch/mips/include/asm/bitops.h:24,
                 from include/linux/bitops.h:17,
                 from include/linux/kernel.h:15,
                 from include/linux/sched.h:52,
                 from arch/mips/kernel/asm-offsets.c:13:
linux-msp71xx/linux-2.6.29/arch/mips/include/asm/war.h:241:2: error: #error Check setting of MIPS34K_MISSED_ITLB_WAR for your
platform

This fixes a compile error when building for the MSP4200 boards.  Identical
patches to fix this were send by

  Florian Fainelli <florian@openwrt.org>
  Shane McDonald <mcdonald.shane@gmail.com>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>