Move arduino_101.conf to boot/zephyr/.

It's currently one level down, in boot/zephyr/targets, from the rest
of the .conf files.

Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
diff --git a/boot/zephyr/targets/arduino_101.conf b/boot/zephyr/arduino_101.conf
similarity index 100%
rename from boot/zephyr/targets/arduino_101.conf
rename to boot/zephyr/arduino_101.conf