gralloc960: Avoid warnings about cutils/log.h

In building for treble I started noticing deprecation
warnings on cutils/log.h. So switch to log/log.h.

Change-Id: Id08ebd0adb00b3ae50875776883fa4104ebb2992
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/gralloc960/legacy/alloc_device.cpp b/gralloc960/legacy/alloc_device.cpp
index fa381fc..6b76948 100644
--- a/gralloc960/legacy/alloc_device.cpp
+++ b/gralloc960/legacy/alloc_device.cpp
@@ -21,7 +21,7 @@
 #include <pthread.h>
 #include <stdlib.h>
 
-#include <cutils/log.h>
+#include <log/log.h>
 #include <cutils/atomic.h>
 #include <hardware/hardware.h>
 #include <hardware/gralloc.h>