ARM: dts: am335x-pcm-953: Remove eth phy delay

Default values fit better than these historical settings.
Hardware layout had been adapted accordingly already in
alpha stage. They did not cause problems for a long time.
Removed values now.

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>