ramips: use hotplug script for EAP615-Wall MACs

ramips: use hotplug script for EAP615-Wall MACs

Using nvmem-cells to set the MAC address for a DBDC device results in
both PHY devices using the same MAC address. This in turn will result in
multiple BSSes using the same BSSID, which can cause various problems.

Use the hotplug script for the EAP615-Wall instead to avoid this.

Fixes: a1b8a4d7b3ff ("ramips: support TP-Link EAP615-Wall")
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Tested-by: Stijn Segers <foss@volatilesystems.org>
Tested-By: Andrew Powers-Holmes <aholmes@omnom.net>
(cherry picked from commit ce90ba1f3168e3f4581fd8581e2c0cd31efa14cf)