arm64: allwinner: sun50i-a64: Correct emac register size

The datasheet said that emac register size is 0x10000 not 0x100

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[wens@csie.org: Fixed commit subject prefix]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>