ARM: dts: mvebu: add support for SolidRun Clearfog GTR

SolidRun Clearfog GTR L8 and S4 SBCs are based on Armada 385. They
features 8 (L8) or 4 (S4) switched Ethernet ports, 1 1Gb Ethernet port,
1 directly connected SFP port, 1 SFP port behind the switch (not
currently described in DT), 3 mini-PCIe slots, eMMC, SPI flash, USB3
port.

  https://developer.solid-run.com/products/clearfog-gtr-a385/



Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>