squelch unwanted "Found SPI device" output

This just demotes a informational print to debug only.

BUG=none
BRANCH=none
TEST=ran on snow, didn't see "Found SPI device spi:spidev on spi1.0"

Change-Id: Ibf84ed70c9219f3baf350b01780fe07325362028
Reviewed-on: https://chromium-review.googlesource.com/175485
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: Gabe Black <gabeblack@chromium.org>
1 file changed