samples: bluetooth: hci_spi: Move dts overlays under boards

Move the dts overlay under a boards/ dir to make it match conf files.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This commit is contained in:
Kumar Gala 2020-03-31 12:02:10 -05:00 committed by Anas Nashif
commit 3f76fa958b