Merge branch 'dsa-realtek-reset'

Luiz Angelo Daros de Luca says:

====================
net: dsa: realtek: support reset controller and update docs

The driver previously supported reset pins using GPIO, but it lacked
support for reset controllers. Although a reset method is generally not
required, the driver fails to detect the switch if the reset was kept
asserted by a previous driver.

This series adds support to reset a Realtek switch using a reset
controller. It also updates the binding documentation to remove the
requirement of a reset method and to add the new reset controller
property.

It was tested on a TL-WR1043ND v1 router (rtl8366rb via SMI).

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
Changes in v5:
- Fixed error checking logic when reset controller (de)assert fails
- Link to v4: https://lore.kernel.org/r/20240219-realtek-reset-v4-0-858b82a29503@gmail.com

Changes in v4:
- do not test for priv->reset,priv->reset_ctl
- updated commit message
- Link to v3: https://lore.kernel.org/r/20240213-realtek-reset-v3-0-37837e574713@gmail.com

Changes in v3:
- Rebased on the Realtek DSA driver refactoring (08f627164126)
- Dropped the reset controller example in bindings
- Used %pe in error printing
- Linked to v2: https://lore.kernel.org/r/20231027190910.27044-1-luizluca@gmail.com/

Changes in v2:
- Introduced a dedicated commit for removing the reset-gpios requirement
- Placed binding patches before code changes
- Removed the 'reset-names' property
- Moved the example from the commit message to realtek.yaml
- Split the reset function into _assert/_deassert variants
- Modified reset functions to return a warning instead of a value
- Utilized devm_reset_control_get_optional to prevent failure when the
  reset control is missing
- Used 'true' and 'false' for boolean values
- Removed the CONFIG_RESET_CONTROLLER check as stub methods are
  sufficient when undefined
- Linked to v1: https://lore.kernel.org/r/20231024205805.19314-1-luizluca@gmail.com/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>