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

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

Change-Id: Iedc22df44537c897c18ac2ca7d5c703a792a247e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>