soc: amlogic: meson-gx-socinfo: Add S905Y2 ID for Radxa Zero

Add the SOC ID for the S905Y2 used in the Radxa Zero. Before/After:

[    0.321650] soc soc0: Amlogic Meson G12A (Unknown) Revision 28:b (30:2) Detected
[    0.318533] soc soc0: Amlogic Meson G12A (S905Y2) Revision 28:b (30:2) Detected

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20210820012718.10761-1-christianshewitt@gmail.com