TDA4VH-Q1: Can the PCIe interface swap lanes and P/N for better layout?

Yes - Polarity inversion should be supported by all PCIe compliant devices.

Thank you. What about swapping of lanes?

Supports standard lane assignments ( TX0 to RX0) or complete lane reversal (TX0 to RX3 for 4Lane PCIe).  No other lane swapping is supported.

What about in 2x2 configuration?

Please clarify '2x2' configuration. 

2 ports with 2 lanes each. So if lane reversal is supported:

Port 1   Tx0 - Rx1

Port 1   Tx1 - Rx0

Port 2   Tx0 - Rx1

Port 2   Tx1 - Rx0

Each PCIe port is a separate entity.  So your question is standard lane reversal, just on two separate PCIe ports.

Ok thanks. And I can reverse just Tx or Rx and not both?

Tx / Rx must go together.   So either standard config or complete reversal for both Tx and Rx.