arm64: dts: allwinner: Remove useless phy-names from EHCI and OHCI

Neither the OHCI or EHCI bindings are using the phy-names property, so we
can just drop it.

Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>