[kernel] Move bind_irq syscall to new system object

In order to implement capabilities on system resources like IRQs so that
they may be restricted to drivers only, add a new 'system' kobject type,
and move the bind_irq functionality from endpoint to system.

Also fix some stack bugs passing the initial handles to a program.

src/kernel/syscalls/system.cpp

@@ -1,8 +1,11 @@
 #include "j6/errors.h"
 #include "j6/types.h"
 
+#include "device_manager.h"
 #include "log.h"
+#include "objects/endpoint.h"
 #include "objects/thread.h"
+#include "syscalls/helpers.h"
 
 namespace syscalls {
 
@@ -25,4 +28,23 @@ system_noop()
 	return j6_status_ok;
 }
 
+j6_status_t
+system_get_log(j6_handle_t sys, j6_handle_t *log)
+{
+	return j6_err_nyi;
+}
+
+j6_status_t
+system_bind_irq(j6_handle_t sys, j6_handle_t endp, unsigned irq)
+{
+	// TODO: check capabilities on sys handle
+	endpoint *e = get_handle<endpoint>(endp);
+	if (!e) return j6_err_invalid_arg;
+
+	if (device_manager::get().bind_irq(irq, e))
+		return j6_status_ok;
+
+	return j6_err_invalid_arg;
+}
+
 } // namespace syscalls