From: Andrew Lunn <andrew@lunn.ch>
Date: Thu, 28 Jan 2016 02:30:28 +0100

White list PHY compatible values which indicate PHYs.  Issue a warning
when one is encountered.

Update the documentation to make it clear what is expected in the
compatible string.

v2:
Fix Grammar, reword changelog, add Tested-by and Acked-by.

Series applied, thanks Andrew.