Support for the EK-TM4C1294XL is provided in the 2.00.00.22 TI-RTOS release available here:
http://software-dl.ti.com/dsps/dsps_public_sw/sdo_sb/targetcontent/tirtos/2_00_00_22/index_FDS.html
However, you'll have to upgrade to CCS 6.0 to use TI-RTOS 2.00.00.22.
CCS 6.0 is scheduled for public release next week and should be available at this website when it is released:
http://processors.wiki.ti.com/index.php/Category:Code_Composer_Studio_v6
Alan