SDL: Add elgext.h header

From 9c1306bc5ebc57ee61e41025ef8b6af81790b8d4 Mon Sep 17 00:00:00 2001
From: Jaylon Gowie <[EMAIL REDACTED]>
Date: Tue, 20 Jul 2021 21:44:16 -0500
Subject: [PATCH] Add elgext.h header

---
 src/video/vita/SDL_vitagl_c.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/video/vita/SDL_vitagl_c.h b/src/video/vita/SDL_vitagl_c.h
index 61d44e4123..9a77d5b0a7 100644
--- a/src/video/vita/SDL_vitagl_c.h
+++ b/src/video/vita/SDL_vitagl_c.h
@@ -25,6 +25,7 @@
 
 #include <pib.h>
 #include <EGL/egl.h>
+#include <EGL/eglext.h>
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>