pkg/emlearn: bump to 0.12

[aabadie]

Contribution description

As the title says, this PR bumps the emlearn package to the latest 0.12 release. There are no fundamental changes in this release and the test application still works as before.

Testing procedure

• A green CI
• tests/pkg_emlearn works:

BUILD_IN_DOCKER=1 make -C tests/pkg_emlearn/ all test --no-print-directory 
Launching build container using image "riot/riotbuild:latest".
docker run --rm --tty --user $(id -u) -v '/usr/share/zoneinfo/Europe/Paris:/etc/localtime:ro' -v '/work/riot/RIOT:/data/riotbuild/riotbase:delegated' -e 'RIOTBASE=/data/riotbuild/riotbase' -e 'CCACHE_BASEDIR=/data/riotbuild/riotbase' -e 'BUILD_DIR=/data/riotbuild/riotbase/build' -e 'RIOTPROJECT=/data/riotbuild/riotbase' -e 'RIOTCPU=/data/riotbuild/riotbase/cpu' -e 'RIOTBOARD=/data/riotbuild/riotbase/boards' -e 'RIOTMAKE=/data/riotbuild/riotbase/makefiles'        -w '/data/riotbuild/riotbase/tests/pkg_emlearn/' 'riot/riotbuild:latest' make     all
Building application "tests_pkg_emlearn" for "native" with MCU "native".

"make" -C /data/riotbuild/riotbase/pkg/emlearn
"make" -C /data/riotbuild/riotbase/boards/native
"make" -C /data/riotbuild/riotbase/boards/native/drivers
"make" -C /data/riotbuild/riotbase/core
"make" -C /data/riotbuild/riotbase/cpu/native
"make" -C /data/riotbuild/riotbase/cpu/native/periph
"make" -C /data/riotbuild/riotbase/cpu/native/stdio_native
"make" -C /data/riotbuild/riotbase/drivers
"make" -C /data/riotbuild/riotbase/drivers/periph_common
"make" -C /data/riotbuild/riotbase/sys
"make" -C /data/riotbuild/riotbase/sys/auto_init
"make" -C /data/riotbuild/riotbase/sys/test_utils/interactive_sync
   text	   data	    bss	    dec	    hex	filename
  69151	    628	  47748	 117527	  1cb17	/data/riotbuild/riotbase/tests/pkg_emlearn/bin/native/tests_pkg_emlearn.elf
r
/work/riot/RIOT/tests/pkg_emlearn/bin/native/tests_pkg_emlearn.elf /dev/ttyACM0 
RIOT native interrupts/signals initialized.
LED_RED_OFF
LED_GREEN_ON
RIOT native board initialized.
RIOT native hardware initialization complete.

Help: Press s to start test, r to print it is ready
READY
s
START
main(): This is RIOT! (Version: 2022.01-devel-20-g17cbab-pr/pkg/emlearn_0.12)
Predicted digit: 6

Issues/PRs references

None