STLink cannot be used with PSoC Programmer or PSoC Creator. There should not be any issue in exporting PSoC Creator project to uVision. After following the instructions given in Help Document [PSoC Creator -> Help-> PSoC Creator Help Topics -> section "Exporting a Design to Keil µVision"]
One more thing I like to add. In the help documentation., it is mentioned that u-Link and J-Link can be used for PRoC device. It seems we haven't tested the PRoC device with the STLink.
My original idea was to work in a linux environment, download stlink utility (linux version) and then connect my CYBLE module through ST-LINK/V2.
I guess I'll have to try this and see if it works.
Thanks for the heads up with the 'keil' method!