cputime: Restore CPU_ACCOUNTING config defaults for PPC64

Commit abf917cd ("cputime: Generic on-demand virtual cputime
accounting") inadvertantly changed the default CPU_ACCOUNTING
config for PPC64.  Repair that.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: ppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: http://lkml.kernel.org/r/20130208141938.f31b7b9e1acac5bbe769ee4c@canb.auug.org.auSigned-off-by: Ingo Molnar <mingo@kernel.org>

init/Kconfig

@@ -332,7 +332,7 @@ config VIRT_CPU_ACCOUNTING
 choice
 	prompt "Cputime accounting"
 	default TICK_CPU_ACCOUNTING if !PPC64
-	default VIRT_CPU_ACCOUNTING if PPC64
+	default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
 
 # Kind of a stub config for the pure tick based cputime accounting
 config TICK_CPU_ACCOUNTING