subsys: dfu: Migrate to new logging subsys

[Olivier-ProGlove]

Migrate from SYS_LOG to LOG logging mechanism.

Signed-off-by: Olivier Martin [email protected]

[codecov-io]

Codecov Report

Merging #9427 into master will increase coverage by 0.98%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #9427      +/-   ##
==========================================
+ Coverage   52.17%   53.15%   +0.98%     
==========================================
  Files         212      216       +4     
  Lines       25892    33259    +7367     
  Branches     5561     7840    +2279     
==========================================
+ Hits        13508    17679    +4171     
- Misses      10126    12805    +2679     
- Partials     2258     2775     +517

Impacted Files	Coverage Δ
lib/posix/clock.c	78.57% <0%> (-21.43%)	⬇️
subsys/net/ip/tcp_internal.h	48.27% <0%> (-1.73%)	⬇️
include/misc/stack.h	90.9% <0%> (-1.4%)	⬇️
include/net/net_pkt.h	84.87% <0%> (-1.34%)	⬇️
lib/mempool/mempool.c	95.07% <0%> (-0.55%)	⬇️
subsys/net/l2/ethernet/arp.c	53.87% <0%> (-0.19%)	⬇️
include/kernel.h	98.38% <0%> (-0.06%)	⬇️
include/net/socket.h	100% <0%> (ø)	⬆️
include/posix/time.h	100% <0%> (ø)	⬆️
subsys/net/ip/ipv6.h	100% <0%> (ø)	⬆️
... and 56 more

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[nordic-krch]

lgtm

[nordic-krch]

Personally, I would prefer IMG_MANAGER_LOG_LEVEL.

[nashif]

addressed in #10029