SDL: Fixed compiling for Raspberry Pi

From 4e5839a5f4a09afd046b3ea4c16f0d4d542a8e28 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Fri, 26 Nov 2021 13:45:08 -0800
Subject: [PATCH] Fixed compiling for Raspberry Pi

---
 src/video/SDL_egl.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/video/SDL_egl.c b/src/video/SDL_egl.c
index f9cdcda0a2..0ca00530c9 100644
--- a/src/video/SDL_egl.c
+++ b/src/video/SDL_egl.c
@@ -30,6 +30,9 @@
 #include "../core/android/SDL_android.h"
 #include "../video/android/SDL_androidvideo.h"
 #endif
+#if SDL_VIDEO_DRIVER_RPI
+#include <unistd.h>
+#endif
 
 #include "SDL_sysvideo.h"
 #include "SDL_egl_c.h"