ARM: dts: msm: Modify the AggNoc gateway bus clock on msm8996

Modify the bus-clock that the gateway nodes from the Agg Nocs to SNOC
belong to . This is needed because the Agg Noc clocks are RPM
managed and due to clock tree complications don't permit setting a rate
on them rather can be only requested ON or OFF ; because Agg Noc clocks
are ultimately children of SNOC bus clock, some usecases suffer because
SNOC is running slower than expected.
To work around this issue, make the gateway from the Agg Nocs to SNOC be
to be belonging to SNOC this should correct the clock calcuation for
SNOC.

Change-Id: Ia342a45d040f5ca01b44a3cb5e6cab435ef7ff6f
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>