Revert "ARM: dts: msm: Disable runtime PM in host mode for automotive"

'Commit f09d23c34f2f ("ARM: dts: msm: Disable runtime PM in host
mode for automotive")' was disabling runtime PM in host mode for
automotive targets. This lead to leakage being observed on 1.8V
regulator for the USB2 PHY in target RBSC state. Revert this to
avoid the leakage.

Change-Id: Ia5da723764c289612d74287af8cf87f22e852abb
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>