android, mesa_gen_matypes: pull in timespec POSIX definition

This fixes:
  include/c11/threads_posix.h: In function 'cnd_timedwait':
  include/c11/threads_posix.h:140:21: error: storage size of 'abs_time' isn't known

Cc: "10.1 10.2" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Adrian Negreanu <adrian.m.negreanu@intel.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>

src/mesa/Android.libmesa_glsl_utils.mk

@@ -56,6 +56,7 @@ include $(CLEAR_VARS)
 
 LOCAL_MODULE := libmesa_glsl_utils
 LOCAL_IS_HOST_MODULE := true
+LOCAL_CFLAGS := -D_POSIX_C_SOURCE=199309L
 
 LOCAL_C_INCLUDES := \
 	$(MESA_TOP)/src/glsl \

src/mesa/Android.mesa_gen_matypes.mk

@@ -33,6 +33,7 @@ include $(CLEAR_VARS)
 
 LOCAL_MODULE := mesa_gen_matypes
 LOCAL_IS_HOST_MODULE := true
+LOCAL_CFLAGS := -D_POSIX_C_SOURCE=199309L
 
 LOCAL_C_INCLUDES := \
 	$(MESA_TOP)/src/mapi \