Adding third-party source with Apache-2.0 license

[Duc Doan]

Dear all,

I am working on a project that needs to include ST's STM32F4 HAL into
RTEMS, specifically release v1.27.1 at:
https://github.com/STMicroelectronics/STM32CubeF4. However, the CMSIS
files in this repository have Apache-2.0 license. What do you think
about this? Should I add them to RTEMS, or is there anything I need to
do to include these sources?

Thank you,

Duc Doan