apm821xx: meraki-mx60: fix ubootenv definitions

apm821xx: meraki-mx60: fix ubootenv definitions

Needed to avoid probe errors.

There are two partitions from 0-20000 and 80000-100000.

This is redundant-count and not regular u-boot,env

Add status = "disabled" as the u-boot env driver can't handle redundant
environments properly. As a result, fw_printenv ends up not working
right.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/16618
(cherry picked from commit 23bb631c4a6fdbd2f63a48804a5c5377e2661122)
Link: https://github.com/openwrt/openwrt/pull/22339
Signed-off-by: Robert Marko <robimarko@gmail.com>