ARM: meson: display Amlogic SoC Information

The Amlogic SoCs have a registers containing the die revision
and packaging type to determine the SoC family and package marketing
name like S905X for the GXL SoC Family.

This code is taken from the Linux meson-gx-socinfo driver and adapted
to U-Boot printing.

Signed-off-by: Julien Masson <jmasson@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
[narmstrong: also updated new p200/p201 defconfigs]