staging: mt7621-dts: fix LEDs and pinctrl on GB-PC1 devicetree

staging: mt7621-dts: fix LEDs and pinctrl on GB-PC1 devicetree

Fix LED and pinctrl definitions on the GB-PC1 devicetree. Refer to the
schematics of the device for more information.

LED fixes:
- Change GPIO6 LED label from system to power as GPIO6 is connected to
PLED.
- Add default-on default-trigger to power LED.
- Change GPIO8 LED label from status to system as GPIO8 is connected to
SYS_LED.
- Add disk-activity default-trigger to system LED.
- Switch to the color:function naming scheme.
- Remove lan1 and lan2 LEDs as they don't exist.

Pinctrl fixes:
- Claim state_default node under pinctrl node.
- Change pinctrl0 node name to state-default.
- Change gpio node name to gpio-pinmux to respect
Documentation/devicetree/bindings/pinctrl/ralink,rt2880-pinmux.yaml.
- Sort pin groups alphabetically.

Misc fixes:
- Fix formatting.
- Use the status value "okay".
- Define hexadecimal addresses in lower case.
- Make hexadecimal addresses for memory easier to read.

Link: https://github.com/ngiger/GnuBee_Docs/blob/master/GB-PCx/Documents/GB-PC1_V1.0_Schematic.pdf
Tested-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Link: https://lore.kernel.org/r/20220311090320.3068-1-arinc.unal@arinc9.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>