PSoC 6 doesn't have the Switched Capacitor / Continuous Time (SC/CT) blocks found in PSoC 5LP, which can form TIAs without any external components. However, you can use the CTBm Opamps of PSoC 6 with external resistors to form TIAs. This configuration also provides better gain accuracy and linearity than SC/CT based TIA.
Following image shows an example of PSoC 6 Opamp based TIA feeding an ADC input. Note that you need to configure the "Output drive" option of the Opamp component to "Output to pin" to use this arrangement.