Add new option to be able to perform upgrade on current partition for dual firmware devices:
"-s stay on current partition (for dual firmware devices)"
Signed-off-by: Paweł Owoc <frut3k7@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/14720
Link: https://github.com/openwrt/openwrt/pull/20086
Signed-off-by: Robert Marko <robimarko@gmail.com>
(cherry picked from commit e0478edeedccd10164b99cdba915776fcc6843c4)