Hello @5angxr,
It is not a problem to use "CLOCK_EnableClock(kCLOCK_Xbar1);" twice, this because the clock will be enabled.
Also, to know if the clock is enabled you can see the bits 22 and 23 in the register called "CCM Clock Gating Register 2" where is in the chapter 14.7.23 in the RM. As shows the next image:

Also, if you experience any issue, do not hesitate to let me know.
BR
Habib