SDL: N3DS: Set keyboard focus to newly created windows.

SDL Commits
1 
From 80ff20f6fe15fdba95fb1c49cfdc855a12e6eea1 Mon Sep 17 00:00:00 2001
From: Pierre Wendling <[EMAIL REDACTED]>
Date: Mon, 14 Nov 2022 23:56:20 -0500
Subject: [PATCH] N3DS: Set keyboard focus to newly created windows.

This fixes polling issues with Joystick subsystem where
`SDL_PrivateJoystickShouldIgnoreEvent` would always return true, thus
ignoring all inputs.
---
 src/video/n3ds/SDL_n3dsvideo.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/video/n3ds/SDL_n3dsvideo.c b/src/video/n3ds/SDL_n3dsvideo.c
index 73486e653ac8..d4a46ad065d9 100644
--- a/src/video/n3ds/SDL_n3dsvideo.c
+++ b/src/video/n3ds/SDL_n3dsvideo.c
@@ -178,6 +178,7 @@ N3DS_CreateWindow(_THIS, SDL_Window *window)
     display_data = (DisplayDriverData *) SDL_GetDisplayDriverData(window->display_index);
     window_data->screen = display_data->screen;
     window->driverdata = window_data;
+    SDL_SetKeyboardFocus(window);
     return 0;
 }