arm64: dts: msm8916: Correct ipc references for smsm

SMSM is not symmetrical, the incoming bits from WCNSS are available at
index 6, but the outgoing host id for WCNSS is 3. Further more, upstream
references the base of APCS (in contrast to downstream), so the register
offset of 8 must be included.

Fixes: 1fb47e0a

 ("arm64: dts: qcom: msm8916: Add smsm and smp2p nodes")
Cc: stable@vger.kernel.org
Reported-by: Ramon Fried <rfried@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>