trace, RAS: Add basic RAS trace event

To avoid confuision and conflict of usage for RAS related trace event,
add an unified RAS trace event stub.

Start a RAS subsystem menu which will be fleshed out in time, when more
features get added to it.

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1402475691-30045-2-git-send-email-gong.chen@linux.intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>

drivers/ras/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_RAS) += ras.o