android/avd/util.c: Translate arm64-v8a ABI to arm64 CPU architecture.

This tiny patch is necessary to ensure that the 'emulator' launcher
properly picks up the right emulation engine (emulator-arm64)

Change-Id: I730ce9525dc2e96aac2c1f47357a3d62daba47e5
diff --git a/android/avd/util.c b/android/avd/util.c
index 51236ac..39e25d9 100644
--- a/android/avd/util.c
+++ b/android/avd/util.c
@@ -170,6 +170,7 @@
         } kData[] = {
             { "armeabi", "arm" },
             { "armeabi-v7a", "arm" },
+            { "arm64-v8a", "arm64" },
         };
         size_t n;
         for (n = 0; n < sizeof(kData)/sizeof(kData[0]); ++n) {