shared/platform.h: remove the local EGL platform (re)definitions

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
diff --git a/shared/platform.h b/shared/platform.h
index e0ed55b..1eb96fd 100644
--- a/shared/platform.h
+++ b/shared/platform.h
@@ -35,9 +35,7 @@
 #include <EGL/eglext.h>
 #endif
 
-#ifndef EGL_PLATFORM_WAYLAND_KHR
-#define EGL_PLATFORM_WAYLAND_KHR 0x31D8
-#endif
+#include "weston-egl-ext.h"
 
 #ifdef  __cplusplus
 extern "C" {
@@ -45,16 +43,6 @@
 
 #ifdef ENABLE_EGL
 
-#ifndef EGL_EXT_platform_base
-typedef EGLDisplay (*PFNEGLGETPLATFORMDISPLAYEXTPROC) (EGLenum platform,
-						       void *native_display,
-						       const EGLint *attrib_list);
-typedef EGLSurface (*PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC) (EGLDisplay dpy,
-								EGLConfig config,
-								void *native_window,
-								const EGLint *attrib_list);
-#endif
-
 static bool
 weston_check_egl_extension(const char *extensions, const char *extension)
 {