Is it against HIPAA Policy to say the customer's name in greeting them at the customer service counter of the Pharmacy?

No. Its just being polite.

No, in fact most of the larger pharmacy even page a customer by name to come to the counter ( if they are waiting on their order)

It may be against your drug stores policy ( I hope not, since it would be rude) if if it is against the policy then you should not be doing it.

What they can not do is say, Mr or Ms "Customer name" here is your blood pressure medication, or other drug name.