ARM: dts: msm: Allow pm_suspend in host mode for msm8996 ADP

This change adds device tree flag to allow system suspend
on automotive platform with USB devices connected that do
not support runtime suspend.

Change-Id: I3ddda5052c866e16c46e5a46255acc28ab6f9363
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>