rmodule: add rmodules class and new type

Add an rmodules class so that there are default rules for compiling
files that will be linked by the rmodule linker. Also, add a new type
for SIPI vectors.

Change-Id: Ided9e15577b34aff34dc23e5e16791c607caf399
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2751
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/include/rmodule.h

@@ -26,6 +26,7 @@
 
 enum {
 	RMODULE_TYPE_SMM,
+	RMODULE_TYPE_SIPI_VECTOR,
 };
 
 struct rmodule;