PCI: tegra194: Rename tegra_pcie_dw to tegra194_pcie

Rename tegra_pcie_dw to tegra194_pcie to match the convention of
<driver>_pcie. No functional change intended.

[bhelgaas: rename functions similarly]
Link: https://lore.kernel.org/r/20211223011054.1227810-20-helgaas@kernel.org
Signed-off-by: Fan Fei <ffclaire1224@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>