Fixed a configure bug.

Should check the enable-glamor-gles2 before use the variable.
And should include the config.h as the GLAMOR_GLES2 macro is
defined there.

Signed-off-by: Zhigang Gong <zhigang.gong@linux.intel.com>

glamor/glamor_egl.c

@@ -27,6 +27,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #ifdef HAVE_DIX_CONFIG_H
 #include <dix-config.h>
 #endif

glamor/glamor_priv.h

@@ -27,6 +27,10 @@
 #ifndef GLAMOR_PRIV_H
 #define GLAMOR_PRIV_H
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #ifdef HAVE_DIX_CONFIG_H
 #include <dix-config.h>
 #include <xorg-config.h>