ixgbe: fix media type detection for E610 device

The commit 23c0e5a1 ("ixgbe: Add link management support for E610
device") introduced incorrect media type detection for E610 device. It
reproduces when advertised speed is modified after driver reload. Clear
the previous outdated PHY type high value.

Reproduction steps:
modprobe ixgbe
ethtool -s eth0 advertise 0x1000000000000
modprobe -r ixgbe
modprobe ixgbe
ethtool -s eth0 advertise 0x1000000000000
Result before the fix:
netlink error: link settings update failed
netlink error: Invalid argument
Result after the fix:
No output error

Fixes: 23c0e5a1 ("ixgbe: Add link management support for E610 device")
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Bharath R <bharath.r@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>