uboot-imx

ARM: rmobile: alt: Remove R8A7794_ETHERNET_B

The R8A7794_ETHERNET_B config option is unused and based on the
description, this is a setting which should be fully done on a
DT level instead. Remove this config option.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>