No. That's fine for a law, but as I said, Amendments should be reserved for central concepts to the nation, freedom, liberty, etc... BIG things that are more philosophical standpoints on how the nation views the interaction between itsself and it's people.
A law clarifying that human beings are the only "people" with rights afforded to the people, by the people would be fine. But that's not Amendment material.
If say, in the future, there are several sentient races, be they terrestrial, synthetic, alien or otherwise, then an Amendment stating that the "rights of the people" are limited only to sentient beings, sure, Amendment material.
What disgusts me is that it seems necessary at all. Corporations aren't people. They're the pulpits of people, the puppets of people, the tools, the soapboxes, the creations of people but are not people. Any child can tell you that a chair isn't a person, that a truck isn't a person, that a building, a dollar, or a computer(as far as we've developed them) isn't a person, so why on earth should anyone older than 5 think that a conglomeration of those things is a person? It's ridiculous! The law should be repealed on the basis that it is founded on complete and utter stupidity.
Now there's something I will support as an Amendment: "Laws should be founded on reason and logic."