SDL: N3DS: Don't set `num_display` by hand.

SDL Commits
1 
From efc93e68514851475beb700bf8d250e11bb32117 Mon Sep 17 00:00:00 2001
From: Pierre Wendling <[EMAIL REDACTED]>
Date: Sun, 18 Sep 2022 15:17:08 -0400
Subject: [PATCH] N3DS: Don't set `num_display` by hand.

Doing so creates 2 empty displays at the beginning of the list.
---
 src/video/n3ds/SDL_n3dsvideo.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/video/n3ds/SDL_n3dsvideo.c b/src/video/n3ds/SDL_n3dsvideo.c
index e3f79cb63999..73486e653ac8 100644
--- a/src/video/n3ds/SDL_n3dsvideo.c
+++ b/src/video/n3ds/SDL_n3dsvideo.c
@@ -83,8 +83,6 @@ N3DS_CreateDevice(void)
     device->UpdateWindowFramebuffer = SDL_N3DS_UpdateWindowFramebuffer;
     device->DestroyWindowFramebuffer = SDL_N3DS_DestroyWindowFramebuffer;
 
-    device->num_displays = 2;
-
     device->free = N3DS_DeleteDevice;
 
     return device;