Follow the same approach as other architectures such as Arm or RISC-V,
and build devicetrees based on platforms selected in Kconfig. This makes
it unnecessary to use CONFIG_OF_ALL_DTBS on PowerPC in order to build
DTB files.

This makes it easier to use other build and test infrastructure such as
`make dtbs_check`, and is a first step towards generating FIT images
that include all the relevant DTBs with `make image.fit`.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260315-mpc83xx-dtb-v4-1-243849be4280@posteo.net

These are the remaining PowerPC devicetrees that do not have a /model
property, even though it is required by the devicetree specification.
Fix them by simply copying the compatible string.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260313-ppc-model-v1-2-bf19b3d1b65d@posteo.net

The mpc8315erdb devicetree did thus far not have a /model property, even
though it is required by the devicetree specification.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260313-ppc-model-v1-1-bf19b3d1b65d@posteo.net

Adjust the name of the drive slot LED node to comply with the schema in
Documentation/devicetree/bindings/leds/leds-gpio.yaml.

  arch/powerpc/boot/dts/wii.dtb: gpio-leds: 'drive-slot' does not match
  any of the regexes: '(^led-[0-9a-f]$|led)', 'pinctrl-[0-9]+'

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260311-wii-schema-v1-3-1563ac4aefa8@posteo.net

Adjust the names of GPIO key nodes to comply with the schema in
Documentation/devicetree/bindings/input/gpio-keys.yaml.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260311-wii-schema-v1-2-1563ac4aefa8@posteo.net

This fixes the following dtschema warning:

  arch/powerpc/boot/dts/wii.dtb: /: memory: False schema does not allow
  {'device_type': ['memory'], 'reg': [[0, 25165824], [268435456, 67108864]]}

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260311-wii-schema-v1-1-1563ac4aefa8@posteo.net

This fixes dtschema warnings such as the following:

  arch/powerpc/boot/dts/mpc8315erdb.dtb: /: memory: False schema
  does not allow {'device_type': ['memory'], 'reg': [[0, 134217728]]}

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303-mpc83xx-cleanup-v2-5-187d3a13effa@posteo.net

These properties are required by the spi-controller binding.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303-mpc83xx-cleanup-v2-4-187d3a13effa@posteo.net

The leds-gpio.yaml schema requires that GPIO LED nodes contain "led",
and preferably start with "led-"

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303-mpc83xx-cleanup-v2-3-187d3a13effa@posteo.net

This increases readability, because "0x8" isn't very descriptive.

mpc8315erdb.dtb remains identical after this patch.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303-mpc83xx-cleanup-v2-2-187d3a13effa@posteo.net