device: s/Z_DEVICE_DT_DEV_NAME/Z_DEVICE_DT_DEV_ID

Rename Z_DEVICE_DT_DEV_NAME to Z_DEVICE_DT_DEV_ID to make it more clear,
as the macro is generating a token that identifies the created struct
device.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>