regulator: pca9450: link regulator inputs to supply groups

regulator: pca9450: link regulator inputs to supply groups

Add supply_name entries for all PCA9450 regulators to describe their
respective input pin groups (INB13, INB26, INB45, INL1). This links each
buck and LDO to the upstream supply that powers its input group.

On some systems, power faults such as undervoltage are detected before
the PMIC itself. Defining supply relationships allows the regulator
framework to propagate such events properly through the dependency
chain.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20251027124415.989301-3-o.rempel@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>