add Spinel SPI interface support am: 7ae6d6f4ff am: 7e9e8e975c am: 0191fa36cf

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2648140

Change-Id: I6c109788b2c4442ce93e14d2da5b3e4d8588d807
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>