imx: cortexa53: remove KSZ9477 static driver

imx: cortexa53: remove KSZ9477 static driver

The KSZ9477 driver was added to the cortexa53 kernel to support the
Gateworks Venice product family which has a board with this switch. Now
that the kmod-dsa-ksz9477 driver is available as a package remove the
static configuration ad add the package.

This resolves an issue caused by having the switch driver static and the
PHY driver as a module such that the PHY driver was not registered early
enough to be used causing some errata to not be worked around.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Link: https://github.com/openwrt/openwrt/pull/22120
Link: https://github.com/openwrt/openwrt/pull/22257
Signed-off-by: Robert Marko <robimarko@gmail.com>