arm64: dts: meson: sync dt and bindings from v5.6-rc2

Sync the device tree and dt-bindings from Linux v5.6-rc2
11a48a5a18c6 ("Linux 5.6-rc2")

The only exception to this is the mmc pinctrl pin bias of gxl SoC family.
This is a fix which found its way to u-boot but not Linux yet.

Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>