SDL: PSP fullscreen is the only mode (#13125)

SDL Commits
1 
From 9b025e3cab64a56331e9c02783ea833ae1211d48 Mon Sep 17 00:00:00 2001
From: Sander Ledegen <[EMAIL REDACTED]>
Date: Mon, 26 May 2025 19:31:48 +0200
Subject: [PATCH] PSP fullscreen is the only mode (#13125)

---
 src/video/psp/SDL_pspvideo.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/video/psp/SDL_pspvideo.c b/src/video/psp/SDL_pspvideo.c
index 2458235ee2867..afdb6bbae3b28 100644
--- a/src/video/psp/SDL_pspvideo.c
+++ b/src/video/psp/SDL_pspvideo.c
@@ -118,6 +118,8 @@ static SDL_VideoDevice *PSP_Create(void)
 
     device->PumpEvents = PSP_PumpEvents;
 
+    device->device_caps = VIDEO_DEVICE_CAPS_FULLSCREEN_ONLY;
+
     return device;
 }