There is no pga for PSoC4. You may use an OpAmp component and connect some resistors externally to adjust for the needed gain.
One way of making a PGA, SAR is set to use bypassed Vref in order
to get Vref for OpAmp. You can change the mux to switch the fdbk
loop. Might get a little less G error due to Mux Rdson. And better Zin
to the OpAmp. Also mux allows more than one switch on at a time so
possible to get 16 gains out of 4 R's.
Don't forget to bypass P1_7, the ref bypass option of SAR.