powerpc/64: Move HAVE_CONTEXT_TRACKING from pseries to common Kconfig

We added support for HAVE_CONTEXT_TRACKING, but placed the option inside
PPC_PSERIES.

This has the undesirable effect that NO_HZ_FULL can be enabled on a
kernel with both powernv and pseries support, but cannot on a kernel
with powernv only support.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/pseries/Kconfig

@@ -17,7 +17,6 @@ config PPC_PSERIES
 	select PPC_UDBG_16550
 	select PPC_NATIVE
 	select PPC_DOORBELL
-	select HAVE_CONTEXT_TRACKING
 	select HOTPLUG_CPU if SMP
 	select ARCH_RANDOM
 	select PPC_DOORBELL