lantiq: xrx200: add alternative names for Plusnet Hub One and BT Business Hub 5A

lantiq: xrx200: add alternative names for Plusnet Hub One and BT Business Hub 5A

The Plusnet Hub One and BT Business Hub 5A have the same hardware as
the BT Home Hub 5A. This commit adds alternative names so that both
devices can be easily found in the firmware selector.

Signed-off-by: Aleksander Jan Bajkowski <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/17583
Signed-off-by: Hauke Mehrtens <[email protected]>
(cherry picked from commit 1b045a7c13aeb141e0c069aaf5fc38989eee11cf)