ARM: dts: msm: Add SDM845 Interposer SDM670 support

Add initial Interposer support on SDM845 for SDM670.
This also adds the PM660/PM660L nodes and deletes all
occurrences of PM8998.

Change-Id: I9f7d4a4f3f54eeef9b35b7e9fb572c368e888a62
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>