arm64: dts: meson: alpa sort the board Makefile

Let's alpha-sort the board Makefile to keep things organised.

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20220409064257.24453-1-christianshewitt@gmail.com