ARM: dts: msm: Opt-out PCIe TBU from halting

When the PCIe TBU gets halted due to atos debugging, any traffic
that the PCIe master sends gets halted on TBU/NNOC and any
transaction sent to PCIe slave from CPU gets hanged as well because
of the dependency on PCIe master to finish the transaction. Due to
CPU being hanged, there is no way to unhalt the TBU by SW and the
system enters into deadlock. Avoid such scenarios from occurring by
opting-out PCIe TBU from being halted.

Change-Id: I83f3a06cdfe509c458369ea8a550c1184a9d49ff
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>