stock dividend reported by stock company and again by brokerage. can i skip one?

Yes, if the dividend is definitely a duplication, you can and should delete one instance of the 1099-DIV. 

That being said, please make sure that it is a duplication and not just a case where the two companies each reported half because of a name change, or an ownership change. 

if they are in fact duplicates I would not delete/or omit one. That's because the IRS is going to get 2 and look for 2 on your return. It has no way of knowing they're duplicates. Omit one and you're likely to get a bill or notice from the iRS. My preference  would be to report both. then on the stock company 1099-div use the other adjustment box to adjust the net amount reported to zero