PCI: mobiveil: Fix devfn check in mobiveil_pcie_valid_device()

PCI: mobiveil: Fix devfn check in mobiveil_pcie_valid_device()

Current check for devfn number in mobiveil_pci_valid_device() is
wrong in that it flags as invalid functions present in PCI device 0
in the root bus while it is perfectly valid to access all functions
in PCI device 0 in the root bus.

Update the check in mobiveil_pci_valid_device() to fix the issue.

Fixes: 9af6bcb11e12 ("PCI: mobiveil: Add Mobiveil PCIe Host Bridge IP driver")
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Minghuan Lian <Minghuan.Lian@nxp.com>