ARM: dts: msm: Add eMMC slave node on sdm670

Add eMMC slave node to the bus topology so that clients
can vote for the bandwidth on sdm670.
Also add the new eMMC salve id for the same.

Change-Id: I2f71ced04546a550a41a2a95624b90eeb6601d6d
Signed-off-by: Odelu Kukatla <okukatla@codeaurora.org>