Generating a clock from timer using PWM
This being a newer chip from TI there is not a whole lot of application information for it as yet. Even the current data sheet is not very helpful.

Here is one example of using the PWM capabilities of CC26XX series chips at a 1Mhz timer frequency.  

https://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/p/405132/1435673#1435673

The resolution of the Timer is determined by the base clock, the counter setup (eg.: 16 or 32 bit) and the division values being used, (per the example see the values of: PWM_DIV_FACTOR, TIMER_LOADSET, and TIMER_MATCH). 

You may also want to review the TI SmartRF06 board that is mentioned in the link.