arm64: a37xx: Handle pin controls in early board init

arm64: a37xx: Handle pin controls in early board init

Fix the default pin control values in a board-specific
function on early board init stage.
This fix allows the NETA driver to work in RGMII
mode until the full-featured pin control driver gets
introduced.

Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Igal Liberman <igall@marvell.com>
Cc: Nadav Haklai <nadavh@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>