glsl: remove explicit __STDC_FORMAT_MACROS define

Correctly handled by all the build systems.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>

src/compiler/glsl/glsl_parser_extras.cpp

@@ -20,7 +20,6 @@
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  */
-#define __STDC_FORMAT_MACROS 1
 #include <inttypes.h> /* for PRIx64 macro */
 #include <stdio.h>
 #include <stdarg.h>