ext: stm32cube: update stm32f3xx cube version

Update Cube version for STM32F3XX family
from version: V1.6.0
to version: V1.7.0

Minor update
Changes from official delivery:
*dos2unix applied
*trailing white spaces removed

Change-Id: I6ff19632cab6e8350f19aa7e17063c05ec36898f
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>