powerpc/6xx: CONFIG_MCU_MPC8349EMITX cannot be a module

powerpc/6xx: CONFIG_MCU_MPC8349EMITX cannot be a module

During "make ppc6xx_defconfig" the following happens:

  HOSTCC  scripts/basic/fixdep
  GEN     /usr/local/src/tmp/lnx/Makefile
  HOSTCC  scripts/kconfig/conf.o
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
arch/powerpc/configs/ppc6xx_defconfig:74:warning: symbol value 'm' invalid for MCU_MPC8349EMITX

Setting CONFIG_MCU_MPC8349EMITX=y in ppc6xx_defconfig makes the warning
go away. This too has been reported by Geert Uytterhoeven a long time ago:
https://lkml.org/lkml/2011/11/13/11  - I only came across this because I
needed a "clean" defconfig for this Powerbook G5.

Signed-off-by: Christian Kujau <lists@nerdbynature.de>
[scottwood@freescale.com: cleaned up commit message slightly]
Signed-off-by: Scott Wood <scottwood@freescale.com>