PCI: Drop duplicate pcie_get_speed_cap(), pcie_get_width_cap() declarations

PCI: Drop duplicate pcie_get_speed_cap(), pcie_get_width_cap() declarations

6cf57be0f78e ("PCI: Add pcie_get_speed_cap() to find max supported link
speed") and c70b65fb7f12 ("PCI: Add pcie_get_width_cap() to find max
supported link width") added declarations to drivers/pci/pci.h.

576c7218a154 ("PCI: Export pcie_get_speed_cap and pcie_get_width_cap")
subsequently added duplicates to include/linux/pci.h.

Remove the originals from drivers/pci/pci.h.  Both interfaces are used by
amdgpu, so they must be in include/linux/pci.h.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Krzysztof Wilczyński <kw@linux.com>