ixgbe/base: optimize link up time

ixgbe/base: optimize link up time

This patch adds max_link_up_time parameter to mac structure.
This parameter is used to control maximum link polling time in
ixgbe_check_mac_link functions. It is required to prevent long wait
time on x550 PHY that have no external link.

Since x550 is handled by software, we have to reset internal (PHY to
PHY) link when external link changes, and after reset, we have to wait for
this link to be established. As a result of not having interrupts, we have
to poll for link state, and we know that this link comes up much faster
than default 9 seconds. This parameter is added to prevent waiting 9
seconds for link when external link is not established.

Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
Acked-by: Helin Zhang <helin.zhang@intel.com>