deb: recommend the correct hostmot2 package

The correct name for the hostmot2 firmware package to Recommend is
"hostmot2-firmware-all".

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
Merge remote-tracking branch 'seb-gh/seb/2.6/fix-recommends-hm2' into 2.6

Signed-off-by: Jeff Epler <jepler@unpythonic.net>