glesgsg: Only use the iOS GLES framework when "BUILD_IPHONE" is defined

panda/src/gles2gsg/gles2gsg.h

@@ -51,7 +51,7 @@
 // OpenGL ES 2 has no fixed-function pipeline.
 #undef SUPPORT_FIXED_FUNCTION
 
-#ifdef IS_OSX
+#ifdef BUILD_IPHONE
   #include <OpenGLES/ES2/gl.h>
 // #include <OpenGLESES2glext.h>
 #else

panda/src/glesgsg/glesgsg.h

@@ -54,7 +54,7 @@
 #define __glext_h_
 #define ES1_GLEXT_H_GUARD
 
-#ifdef IS_OSX
+#ifdef BUILD_IPHONE
   #include <OpenGLES/ES1/gl.h>
 // #include <OpenGLESES1glext.h>
 #else