net: phy: dp83867: Fix warning check for setting the internal delay

Fix warning: logical ‘or’ of collectively exhaustive tests is always true

Change the internal delay check from an 'or' condition to an 'and'
condition.

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>