arm64: defconfig: Set qrtr wakeup for genericarmv8

Set the wakeup timeout for qrtr to 500 ms for genericarmv8. This change
will help ensure the TUI client thread gets a chance to run before the
system is suspended again.

Change-Id: Iaaa84e99c0e1f8c29b6e80746440b7d960887193
Signed-off-by: Chris Lew <clew@codeaurora.org>