If it is connected to the pin 32 of the CC1120, then it very much could be a 33.6MHz crystal oscillator.
It might be a TCXO if the device is doing some long range narrowband stuff on 868MHz or 900MHz bands.
TI CC1120 datasheet[1] does give 33.6MHz as the maximum typical value for the reference oscillator.
The oscillation frequency should be relatively easy to confirm by probing the output pin with an oscilloscope.
1. Section 4.9, on page 14
https://www.ti.com/lit/ds/symlink/cc1120.pdf