return ubnt_rocket-m and ubnt_powerbridge-m back to ath79-generic
They have enough RAM-ressources to not be considered as tiny.
This reverts the commit f4415f7635164ec07ddc22f56df93555804b5767 partially
Signed-off-by: Felix Baumann <felix.bau@gmx.de>
(cherry picked from commit 9e86a96af5ecea6e73fa463d6cfa4408e2b49d35)