From memory, the ST7775 is very similar to the ILI9225.
Open-Smart have specific code for each of their displays. I would guess that it is just different initlcd.h files for the UTFT library.
From a brief glance, the initlcd.h files are different. There is no specific ST7775/initlcd.h file but UTFT treats ST7775 as if it is a RM68130 clone.
If you are running MCUFRIEND_kbv, I am happy to help you with ST7775 / RM68130. After all, there are datasheets for both.
I presume that you have downloaded and installed the [OPEN-SMART] TFT2.0inch Breakout include S6D1121 ST7775 ILI9225 RM68130.rar file.
David.