ARM: dts: msm: update sleep vote node for sdm670

Display module keeps fix sleep vote on mnoc, ebi
and llcc. This does not need the split vote because
it is same for all three clients. Single node
creation also reduces the bus vote latency.

Change-Id: I5fd1d32d8301893134c3b5e776b19a1fc8f18491
Signed-off-by: Shubhashree Dhar <dhar@codeaurora.org>