arm/dt: msm8974: Add bus scaling configuration for TSIF

PNOC bus clients need to vote for bus scaling. Since TSIF
is one of those clients, added the required configuration
of bus scaling which is configured by tspp driver when
TSIF interface is enabled.

Change-Id: If095f9fa83160d284b5930b79b910fa2878e2db6
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>