hikey: gralloc Update for new ION interface

4.12+ kernels have an updated ION interface; this adapts hikey's gralloc
to work seemlessly with both old and new kernels' interfaces.

Test: validated with both new and old kernels on hikey, with aosp master

Change-Id: Ia019fd7f3f5b3e9765c8f26032ff0063e5391f56
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
  [sumits: maintain compatibility with older kernels]
diff --git a/gralloc/gralloc_priv.h b/gralloc/gralloc_priv.h
index ab45f8b..71920e0 100644
--- a/gralloc/gralloc_priv.h
+++ b/gralloc/gralloc_priv.h
@@ -112,6 +112,8 @@
 	pthread_mutex_t lock;
 	buffer_handle_t currentBuffer;
 	int ion_client;
+	int system_heap_id;
+	bool gralloc_legacy_ion;
 
 	struct fb_var_screeninfo info;
 	struct fb_fix_screeninfo finfo;