configs: riscv: starfive: Add VF2 PCIe USB3 XHCI support

Add XHCI_PCI to enable usb3-host functions.
Also add usb command and keyboard config.

Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>