mpc85xx: unify wrapper address of simple image devices

mpc85xx: unify wrapper address of simple image devices

The wrapper address of simple image devices should have been changed
at commit 6a8b831 , but only TL-WDR4900 and BR200-WP are changed at
that time, and now the wrapper address changes are split among patches
for specific devices. More importantly, commit 6a8b831 forgot to
change Enterasys WS-AP3715i, causing
https://github.com/openwrt/openwrt/issues/23112 .

This commit will gather the change of wrapper address of simple image
devices into a dedicated patch file.

Tested: Both WS-AP3715i and TL-WDR4900 v1 boot well.

Fixes: https://github.com/openwrt/openwrt/issues/23112
Signed-off-by: Edward Chow <equu@openmail.cc>
Link: https://github.com/openwrt/openwrt/pull/23121
Signed-off-by: Robert Marko <robimarko@gmail.com>