generic: b53: rename exported symbols to avoid upstream conflict

generic: b53: rename exported symbols to avoid upstream conflict

Upstream DSA driver is exporting symbols with the same name as our
downstream swconfig driver, so lets rename the downstream symbols to make
them unique and avoid the conflict on 6.1 kernel.

Without this change, building 6.1 with kmod-switch-bcm53xx would conflict
with the B53 DSA driver and CI would fail.

Signed-off-by: Robert Marko <robimarko@gmail.com>
(cherry picked from commit effccdd444a956afc5493ef8f1c79a7e7ffa8490)