arm64: tegra: Fix Tegra194 PCIe EP compatible string

The initialization sequence performed by the generic platform driver
pcie-designware-plat.c for a DWC based implementation doesn't work for
Tegra194. Tegra194 has a different initialization sequence requirement
which can only be satisfied by the Tegra194 specific platform driver
pcie-tegra194.c. So, remove the generic compatible string "snps,dw-pcie-ep"
from Tegra194's endpoint controller nodes.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>