libcamera: file: Turn MapFlag and OpenModeFlag into enum class

Add type safety by turning the MapFlag and OpenModeFlag enum into enum
class.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

src/libcamera/ipa_manager.cpp

@@ -285,7 +285,7 @@ bool IPAManager::isSignatureValid([[maybe_unused]] IPAModule *ipa) const
 	}
 
 	File file{ ipa->path() };
-	if (!file.open(File::ReadOnly))
+	if (!file.open(File::OpenModeFlag::ReadOnly))
 		return false;
 
 	Span<uint8_t> data = file.map();