Regression for 32-bit ppc on PowerBook G4 Aluminum (bisected to commit d0e3fc69d00d)

[Larry Finger]

Beginning with commit d0e3fc69d00d ("powerpc/vdso: Provide 
__kernel_clock_gettime64() on vdso32"), my PowerBook G4 Aluminum fails to boot. 
It stops pretty early in the boot.

I will be happy to test any patches, or provide any additional information.
Larry