Enabling Capstone build for android-x86_64 arch variant

It looks to be a bug as currently the android.bp supports only arm,arm64 and x86. This change is added to ensure that we have a
valid build with android x86_64 arch variant for this capstone disassembler. We obseved crashes when we tried to
initialize this disassembler with x86_64 intel architecture at runtime. With the changes the capstone disassembler works as expected
for x86_64 variant as well

Test: Existing unit tests passes.

Change-Id: I50c6bf01e32cb4abfb8f319c1c380848a1e42af6
Signed-off-by: Priyanka Bose <priyanka.bose@intel.com>
diff --git a/Android.bp b/Android.bp
index f580d14..c5c43c2 100644
--- a/Android.bp
+++ b/Android.bp
@@ -53,6 +53,10 @@
             cflags: arm_flags + arm64_flags + x86_flags,
             srcs: arm_srcs + arm64_srcs + x86_srcs,
         },
+	x86_64: {
+            cflags: arm_flags + arm64_flags + x86_flags,
+            srcs: arm_srcs + arm64_srcs + x86_srcs,
+        },
         arm64: {
             cflags: arm_flags + arm64_flags,
             srcs: arm_srcs + arm64_srcs