ARM: dts: msm: Change UART wakelock settings for apq8084 boards

Switch the configurable rx/tx wakelock holding configuration
from 500ms to 0ms. With this change the UART wakelock is
release immediately when rx/tx buffer is empty.

Change-Id: Id170310f5cc5688e19632a8881fac048c0d1ef0c
Signed-off-by: Mika Vesalainen <mikavesa@codeaurora.org>
Signed-off-by: Roman Gezikov <rgezikov@codeaurora.org>