net: pse-pd: Kconfig: Add missing Regulator API dependency

The PSE (Power Sourcing Equipment) API now relies on the Regulator API.
However, the Regulator dependency was missing from Kconfig. This patch
adds the necessary dependency, resolving the issue of the missing
dependency and ensuring proper functionality of the PSE API.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404201020.mqX2IOu7-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202404200036.D8ap1Mf5-lkp@intel.com/
Fixes: d83e13761d5b ("net: pse-pd: Use regulator framework within PSE framework")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://lore.kernel.org/r/20240423-fix_poe-v3-3-e50f32f5fa59@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: pse-pd: Add TI TPS23881 PSE controller driver

Add a new driver for the TI TPS23881 I2C Power Sourcing Equipment
controller.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://lore.kernel.org/r/20240417-feature_poe-v9-14-242293fd1900@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: pse-pd: Add PD692x0 PSE controller driver

Add a new driver for the PD692x0 I2C Power Sourcing Equipment controller.
This driver only support i2c communication for now.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240417-feature_poe-v9-12-242293fd1900@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: pse-pd: PSE_REGULATOR should depend on REGULATOR

The Regulator based PSE controller driver relies on regulator support to
be enabled. If regulator support is disabled, it will still compile
fine, but won't operate correctly.

Hence add a dependency on REGULATOR, to prevent asking the user about
this driver when configuring a kernel without regulator support.

Fixes: 66741b4e94ca7bb1 ("net: pse-pd: add regulator based PSE driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/709caac8873ff2a8b72b92091429be7c1a939959.1664900558.git.geert+renesas@glider.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: pse-pd: add regulator based PSE driver

Add generic, regulator based PSE driver to support simple Power Sourcing
Equipment without automatic classification support.

This driver was tested on 10Bast-T1L switch with regulator based PoDL PSE.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add framework to support Ethernet PSE and PDs devices

This framework was create with intention to provide support for Ethernet PSE
(Power Sourcing Equipment) and PDs (Powered Device).

At current step this patch implements generic PSE support for PoDL (Power over
Data Lines 802.3bu) specification with reserving name space for PD devices as
well.

This framework can be extended to support 802.3af and 802.3at "Power via the
Media Dependent Interface" (or PoE/Power over Ethernet)

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>