regulator: rk808: Restrict DVS GPIOs to the RK808 variant only

The rk808-regulator driver supports multiple PMIC variants from the Rockckip
RK80x and RK81x series, but the DVS GPIOs are supported on the RK808 variant
only, according to the DT bindings [1][2][3][4][5][6] and the datasheets for
the supported PMIC variants. [7][8][9][10][11][12]

Thus, change the probe path so the "dvs-gpios" property is checked for and
its value possibly used only when the handled PMIC variant is RK808.  There's
no point in doing that on the other PMIC variants, because they don't support
the DVS GPIOs, and it goes against the DT bindings to allow a possible out-
of-place "dvs-gpios" property to actually be handled in the driver.

This eliminates the following messages, emitted when the "dvs-gpios" property
isn't found in the DT, from the kernel log on boards that actually don't use
the RK808 variant, which may have provided a source of confusion:

  rk808-regulator rk808-regulator.2.auto: there is no dvs0 gpio
  rk808-regulator rk808-regulator.2.auto: there is no dvs1 gpio

Furthermore, demote these kernel messages to debug messages, because they are
useful during the board bringup phase only.  Emitting them afterwards, on the
boards that use the RK808 variant, but actually don't use the DVS0/1 GPIOs,
clutters the kernel log a bit, while they provide no value and may actually
cause false impression that some PMIC-related issues are present.

[1] Documentation/devicetree/bindings/mfd/rockchip,rk805.yaml
[2] Documentation/devicetree/bindings/mfd/rockchip,rk806.yaml
[3] Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml
[4] Documentation/devicetree/bindings/mfd/rockchip,rk816.yaml
[5] Documentation/devicetree/bindings/mfd/rockchip,rk817.yaml
[6] Documentation/devicetree/bindings/mfd/rockchip,rk818.yaml
[7] https://rockchip.fr/RK805%20datasheet%20V1.2.pdf
[8] https://wmsc.lcsc.com/wmsc/upload/file/pdf/v2/lcsc/2401261533_Rockchip-RK806-1_C5156483.pdf
[9] https://rockchip.fr/RK808%20datasheet%20V1.4.pdf
[10] https://rockchip.fr/RK816%20datasheet%20V1.3.pdf
[11] https://rockchip.fr/RK817%20datasheet%20V1.01.pdf
[12] https://rockchip.fr/RK818%20datasheet%20V1.0.pdf



Fixes: 11375293 ("regulator: rk808: Add regulator driver for RK818")
Reported-by: Diederik de Haas <didi.debian@cknow.org>
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Link: https://patch.msgid.link/9a415c59699e76fc7b88a2552520a4ca2538f44e.1728902488.git.dsimic@manjaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>