iwlwifi: yoyo: use hweight_long instead of bit manipulating

Also we can only have one fid1 or fid2 set so no need to check
if the fid2 is set in case fid1 wasn't set.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200424182644.34e74106bad3.Ic3a9f0a35fed47b02ebcd27c2dc2b50cb1e56bdf@changeid