Add iotop to PRODUCT_PACKAGES_DEBUG

This was previously marked as LOCAL_MODULE_TAGS := debug, and is used
from dumpstate.

Test: iotop is still installed after remove the debug tag
Change-Id: I685456f52403a2d5c6fbbff1429c6af422ce26df
diff --git a/target/product/base.mk b/target/product/base.mk
index e778e76..919c16d 100644
--- a/target/product/base.mk
+++ b/target/product/base.mk
@@ -151,6 +151,7 @@
 
 # Packages included only for eng or userdebug builds, previously debug tagged
 PRODUCT_PACKAGES_DEBUG := \
+    iotop \
     logpersist.start \
     perfprofd \
     sqlite3 \