ramips: fix GB-PC1 and GB-PC2 device support

ramips: fix GB-PC1 and GB-PC2 device support

Change switch port labels to ethblack & ethblue.
Change lan1 & lan2 LEDs to ethblack_act & ethblue_act and fix GPIO pins.
Add the external phy with ethyellow label on the GB-PC2 devicetree.
Do not claim rgmii2 as gpio, it's used for ethernet with rgmii2 function.
Enable ICPlus PHY driver for IP1001 which GB-PC2 has got.
Update interface name and change netdev function.
Enable lzma compression to make up for the increased size of the kernel.
Make spi flash bindings on par with mainline Linux to fix read errors.

Tested on GB-PC2 by Petr.

Tested-by: Petr Louda <petr.louda@outlook.cz>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
(cherry picked from commit 4807bd6a00bcf44dd821047db76a2a799f403cd4)