arm64: dts: uniphier: add clock-names and reset-names to ethernet node

Add clock-names and reset-names because this node recognizes multiple
clocks and resets.  ("ether", and so on, for each)

Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>