parisc: add ftrace (function and graph tracer) functionality

This patch adds the ftrace debugging functionality to the parisc kernel.
It will currently only work with 64bit kernels, because the gcc options -pg
and -ffunction-sections can't be enabled at the same time and -ffunction-sections
is still needed to be able to link 32bit kernels.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

arch/parisc/kernel/parisc_ksyms.c

@@ -153,5 +153,10 @@ EXPORT_SYMBOL(node_data);
 EXPORT_SYMBOL(pfnnid_map);
 #endif
 
+#ifdef CONFIG_FUNCTION_TRACER
+extern void _mcount(void);
+EXPORT_SYMBOL(_mcount);
+#endif
+
 /* from pacache.S -- needed for copy_page */
 EXPORT_SYMBOL(copy_user_page_asm);