Add attention event handling priority logic

All active attention events are gathered and prioritized and the highest
priority event is handled.

Signed-off-by: Ben Tyner <ben.tyner@ibm.com>
Change-Id: Icad55dacb23232801fdbb5995ef8ee3edc7e90f4
diff --git a/attn/attn_handler.hpp b/attn/attn_handler.hpp
index 256145b..5bfe995 100644
--- a/attn/attn_handler.hpp
+++ b/attn/attn_handler.hpp
@@ -23,6 +23,6 @@
  *
  * @param i_breakpoints true = breakpoint special attn handling enabled
  */
-void attnHandler(bool i_breakpoints);
+void attnHandler(const bool i_breakpoints);
 
 } // namespace attn