The dummy read was a left over from an abandoned merge with the existing
support for the SoCFPGA variant of the Designware MAC. It doesn't exist
in either the U-Boot or kernel drivers for the EQOS, thus drop it.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>