[bsp] Add BSP for TM4C1294XL (TI Tiva C Series Connected LaunchPad)
[bsp] modify the uart_driver to fit the new rt-thread serial device driver framework. Modify the template.uvproj for auto generate MDK project.
Merge pull request #1 from RT-Thread/master

pull rt-thread master
[bsp] Add IAR EWARM project template for SCONS project auto generation.
Merge pull request #304 from ArdaFu/master

[bsp] Add BSP for TM4C1294XL (TI Tiva C Series Connected LaunchPad)