Usually there will be one dts file per board. But it seems there are multiple dts files. They are compiling as dtbo files. After changing in the tegra234-p3737-overlay.dtsfile, the 141a0000.pcie is not visible under /sys/devices/platform/ and under /proc/device-tree/pcie@141a0000 folder also the status is disabled.
To disable PCIe C1(pcie@14100000), I have modified in tegra234-p3737-pcie.dtsi which comes under tegra234-p3701-0000-p3737-0000.dts file.