Combine attn handler and openpower hwdiags

The main binary is now openpower-hw-diags. This application will take a
command line option --daemon to load it as a daemon. As a daemon it will
register the attention handler portion of application as the attention
gpio event handler. If the application is not loaded as a daemon it will
operate as a stand alone application which accepts command line options
for requesting hardware analyses and diagnostics operations.

Change-Id: I6210b744cb320873d74a0757928f904ca6296846
Signed-off-by: Ben Tyner <ben.tyner@ibm.com>
diff --git a/attn/attn_handler.service b/attn/attn_handler.service
index 42bbf34..43d3db7 100644
--- a/attn/attn_handler.service
+++ b/attn/attn_handler.service
@@ -5,7 +5,7 @@
 After=mapper-wait@-xyz-openbmc_project-logging.service
 
 [Service]
-ExecStart=/usr/bin/attn_handler
+ExecStart=/usr/bin/openpower-hw-diags --daemon
 Restart=on-failure
 
 [Install]