libcamera: Don't unnecessarily include event_notifier.h

The ipc_unixsocket.h and process.h internal headers don't need to
include event_notifier.h, the former because a forward declaration
suffices, and the latter because it doesn't use event notifiers. Remove
the unnecessary include, and include signal.h instead which is required
and was included indirectly through event_notifier.h.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/internal/ipc_unixsocket.h

@@ -12,10 +12,12 @@
 #include <sys/types.h>
 #include <vector>
 
-#include <libcamera/event_notifier.h>
+#include <libcamera/signal.h>
 
 namespace libcamera {
 
+class EventNotifier;
+
 class IPCUnixSocket
 {
 public:

include/libcamera/internal/process.h

@@ -10,7 +10,7 @@
 #include <string>
 #include <vector>
 
-#include <libcamera/event_notifier.h>
+#include <libcamera/signal.h>
 
 namespace libcamera {
 

src/libcamera/ipc_unixsocket.cpp

@@ -12,6 +12,8 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
+#include <libcamera/event_notifier.h>
+
 #include "libcamera/internal/log.h"
 
 /**