The official MS DDK/WDK does not expose KeGetPcr() for x86, so do
not expose it there as well. Use instead the private NDK definition.
If it were exposed in the DDK/WDK, it would have to be a
multiprocessor-compatible definition.
Note that the broken definition was working only in single-processor
mode, using the PCR static memory pointer value.
The official MS DDK/WDK exposes KeGetPcr() as an alias to such a
PCR value only for IA64, MIPS and PPC, which is of course not great.