Build warning on 32-bit PPC - bisected to commit 989cea5c14be

[Larry Finger]

I am getting the following warning when I build kernel 4.9-git on my PowerBook 
G4 with a 32-bit PPC processor:

  AS      arch/powerpc/kernel/misc_32.o
arch/powerpc/kernel/misc_32.S:299:7: warning: "CONFIG_FSL_BOOKE" is not defined 
[-Wundef]

This problem has been bisected to commit 989cea5c14be ("kbuild: prevent 
lib-ksyms.o rebuilds").

Thanks,

Larry