Standard WaveDAC won't work on P4 as it requires 2-byte transfer to IDAC (opposed to 1-byte transfer on P5). There is old demo project showing RAM-DMA-IDAC arbitrary wave generation on PSoC4M, which might be useful:
I wouldn't bet on PSoC standard library updates. It seems like development of PSoC5-type SoCs (programmable hardware + analog) at Cypress is over, shifting towards standard MC design. My guess this is due to the MC market specifics.