[PATCH] Revert "power: regulator: Add vin-supply for GPIO and Fixed regulators"

[Sune Brian]

- ret = device_get_supply_regulator(dev, "vin-supply", &plat->vin_supply);
- if (ret) {
- debug("Regulator vin regulator not defined: %d\n", ret);
- if (ret != -ENOENT)
- return ret;
- }
-
- if (plat->vin_supply)
- regulator_set_enable_if_allowed(plat->vin_supply, true);
-

This patch resolved the previous boot issue on mail:
[DEBUG] rk3399-nanopi-neo4: SPL SD init may report -5 due to SD power-on timing

Quotes:
"
While testing mainline U-Boot (v2026.01-rc1-00070-ge34d01d23e45) on the
FriendlyARM NanoPi NEO4 (RK3399), I observed that SPL sometimes fails to
initialize the SD card with the following message:

    spl: mmc init failed with error: -5
    SPL: failed to boot from all boot devices
"

So the NanoPI NEO4 boot stall is somehow
caused by the previous regulator patch.
However, this is very puzzling why w/o reverting
mmc works normally but not SD.

So the delay method proposed by Jonas in previous mail
about delay timing is not the actual root case for RK3399
NanoPI NEO4 SD boot stall.

Brian