ARM: dts: msm: Add stop_ack gpio support for lpass and pronto

The stop ack IRQ is a SMP2P GPIO interrupt that is triggered
when a subsystem acknowledges the receipt and processing of the
force stop gpio.
Currently, only modem uses this and is the only one with the
stop_ack gpio property in its dt entry. Add the property to LPASS
and PRONTO subsystem dt entries.

Change-Id: I731d39b7cbc7dbcc0fc574862d4dfc88fb26b729
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>