net: hibmcge: fix the np_link_fail error reporting issue

Currently, after modifying device port mode, the np_link_ok state
is immediately checked. At this point, the device may not yet ready,
leading to the querying of an intermediate state.

This patch will poll to check if np_link is ok after
modifying device port mode, and only report np_link_fail upon timeout.

Fixes: e0306637 ("net: hibmcge: Add support for mac link exception handling feature")
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>