ext: stm32cube: update stm32f7xx cube version

Update Cube version for STM32F7XX family
from version: V1.4.0
to version: V1.6.0

Add support for Low Level API on stm32f7 familly

Change-Id: Iabe18f952d2cf0847bd72ce9d894d4c0cbd4c0f9
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
201 files changed