ARM: dts: msm: enable 11AD keep-radio-on-during-sleep on SDM845

keep_radio_on_during_sleep allows reserving the 11AD connections
during suspend.
In such a case PCIe will suspend to D3hot and the device power
will not be turned off.

Change-Id: Iad51c3979e18efe74c36a9f80fb00c85ec500665
Signed-off-by: Maya Erez <merez@codeaurora.org>