bus: mhi: host: pci_generic: Set DMA mask for VFs

VFs in devices like QDU100 are capable of accessing host memory up to 40
bits, compared to 32 bits used by PFs and other non-SR-IOV capable MHI
devices.

To support this, configure `dma_mask` independently for PFs and VFs, by
introducing a new 'vf_dma_data_width' member in 'mhi_pci_dev_info' struct
and set it to 40 for QDU100.

Signed-off-by: Vivek Pernamitta <quic_vpernami@quicinc.com>
[mani: reworded subject and description]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Link: https://patch.msgid.link/20250912-uevent_vdev_next-20250911-v4-6-fa2f6ccd301b@quicinc.com