net: phy: Increase link up delay in genphy_update_link()

I've noticed that in most cases when genphy_update_link() is called, the
ethernet driver (mt7628-eth in this case) fails with the first ethernet
packets. Resulting in a timeout of the first tftp command. Increasing
the delay in the link check look from 1 to 50 ms and moving it below the
BMSR register read fixes this issue, resulting in a stable ethernet
traffic, even after initial link autonogotiation.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Weijie Gao <weijie.gao@mediatek.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>