Easy man, don't sweat it.
aic94xx : this driver module is for a RAID controller card by adaptec
wd719x : this is for WD7193/7197/7296 model pci card
Do you have a reason to believe that your system contains these devices?
I don't think so. As, @demm above mentioned these are pretty rare devices.
The only reason these modules exist is that they require non-free firmware.
mkinitcpio will now report when all possible firmware cannot
be found for a module.
Users with the "block" hook in their HOOKS may see warnings show up for
missing firmware on some unfamiliar modules during creation of the
fallback image. Please note that these are warnings only and can
generally be ignored. Obviously, if you start seeing warnings about
missing firmware your modules you do use, you'll appreciate this change.
See full message here, https://lists.archlinux.org/pipermail/arch-dev-public/2013-May/024864.html
Frankly, fella I think these packages exist so as to remove the warning messages. :-) :-)