[LIBC] Use RT_USING_LIBC instead of libs option for each compiler
[BSP] use RT_USING_LIBC instead of RT_USING_NEWLIB
Merge pull request #360 from BernardXiong/master

[LIBC] Use RT_USING_LIBC instead of libs option for each compiler
update bsp/mb9bf568r
update armlibc and add examples/file