[nrf fromtree] dfu: boot: mcuboot: fix boot_is_img_confirmed

[mkapala-nordic]

Fix image confirmed for Direct XIP.

Signed-off-by: Fin Maaß [email protected]
(cherry picked from commit e3f9356)

[nordicjm]

Not needed, will be brought in as part of #2411

[mkapala-nordic]

Not needed, will be brought in as part of #2411

We would like to have it before 3.0.0-preview1 as we need it for our app, will the upmerge be finalized till then?

[nordicjm]

Not needed, will be brought in as part of #2411

We would like to have it before 3.0.0-preview1 as we need it for our app, will the upmerge be finalized till then?

The upmerge will be concluded before 3.0.0 is released, yes

[mkapala-nordic]

Not needed, will be brought in as part of #2411

We would like to have it before 3.0.0-preview1 as we need it for our app, will the upmerge be finalized till then?

The upmerge will be concluded before 3.0.0 is released, yes

Discussed with @anangl.
This change can be merged in this PR rather than wait for the upmerge to be finalized as we need it as soon as possible (not for final 3.0.0 but we would like to have it for 3.0.0-preview1 which is supposed to happen next week).