gralloc: switch to UMP-only allocations

Change-Id: I824855ce742f44669472f6d6176beea674137f64

exynos4/hal/libgralloc_ump/alloc_device.cpp

@@ -296,6 +296,7 @@ static int gralloc_alloc_buffer(alloc_device_t* dev, size_t size, int usage,
     }
 
     ret = -1;
+#if 0
     if (usage & (GRALLOC_USAGE_HW_COMPOSER | GRALLOC_USAGE_HW_ION)) {
         ALOGV("%s: Allocating for HWC via ION...", __func__);
         // the handle is guaranteed to have this usage flag set
@@ -306,6 +307,7 @@ static int gralloc_alloc_buffer(alloc_device_t* dev, size_t size, int usage,
         priv_alloc_flag = priv_alloc_flag | private_handle_t::PRIV_FLAGS_GRAPHICBUFFER;
         ret = gralloc_alloc_ion(dev, size, usage, format, &ion_fd, &ion_paddr, &priv_alloc_flag, &ump_mem_handle);
     }
+#endif
 
     if (ret < 0) {
         // may happen if ion carveout is out of memory, or if the