Add libion to the generic sytem image for camera

Camera HAL is using libion. I believe libion is generic library, so put
it in this generic system image.

Bug: 36043196
Test: make, flash and check that libion.so is in /system/lib.
Change-Id: I2e6b68e5899e27c603476ad7c5cd64f3cd5a8c53
diff --git a/target/product/aosp_arm64_ab.mk b/target/product/aosp_arm64_ab.mk
index 925c823..e7fccd7 100644
--- a/target/product/aosp_arm64_ab.mk
+++ b/target/product/aosp_arm64_ab.mk
@@ -104,6 +104,7 @@
     libtinyalsa \
     libtinycompress \
     cplay \
+    libion \
 
 # WiFi
 # Note: Wifi HAL (android.hardware.wifi@1.0-service, wpa_supplicant,