sf: Enable swaprect optimization by default only on QCOMs

 * This is confirmed to cause problems at least on i9500.
 * Only enable it by default on QCOMs, other devices can opt
   in using the system property.

Change-Id: Ic00137201f4a5383877f4033473c1ea5ac32a3a7
binder: add compat getCallingUidEv symbol

-needed for Nvidia's (T4) powerservice

-merged from: http://goo.gl/SFrxzK

Change-Id: I1e27583ec4b08147d31cb1976ea49336e451e0b6