ftrace: add have dynamic ftrace config for archs

Now that ftrace is being ported to other architectures, it has become
apparent that DYNAMIC_FTRACE is dependent on whether or not that
architecture implements dynamic ftrace. FTRACE itself may be ported to
an architecture without porting dynamic ftrace.

This patch adds HAVE_DYNAMIC_FTRACE to allow architectures to port ftrace
without having to also port the dynamic aspect as well.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 62d034a..a5e9912 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -105,6 +105,7 @@
 config PPC
 	bool
 	default y
+	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FTRACE
 	select HAVE_IDE
 	select HAVE_KPROBES