powerpc: enable dynamic ftrace

This patch enables dynamic ftrace. The PowerPC port was dependent on
other code not yet in mainline. Now that the code is, we can now
let PowerPC compile with dynamic ftrace.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/Kconfig

@@ -108,6 +108,8 @@ config ARCH_NO_VIRT_TO_BUS
 config PPC
 	bool
 	default y
+	select HAVE_FTRACE_MCOUNT_RECORD
+	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FUNCTION_TRACER
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select HAVE_IDE