hsr: Simplify code for announcing HSR nodes timer setup

hsr: Simplify code for announcing HSR nodes timer setup

Up till now the code to start HSR announce timer, which triggers sending
supervisory frames, was assuming that hsr_netdev_notify() would be called
at least twice for hsrX interface. This was required to have different
values for old and current values of network device's operstate.

This is problematic for a case where hsrX interface is already in the
operational state when hsr_netdev_notify() is called, so timer is not
configured to trigger and as a result the hsrX is not sending supervisory
frames to HSR ring.

This error has been discovered when hsr_ping.sh script was run. To be
more specific - for the hsr1 and hsr2 the hsr_netdev_notify() was
called at least twice with different IF_OPER_{LOWERDOWN|DOWN|UP} states
assigned in hsr_check_carrier_and_operstate(hsr). As a result there was
no issue with sending supervisory frames.
However, with hsr3, the notify function was called only once with
operstate set to IF_OPER_UP and timer responsible for triggering
supervisory frames was not fired.

The solution is to use netif_oper_up() and netif_running() helper
functions to assess if network hsrX device is up.
Only then, when the timer is not already pending, it is started.
Otherwise it is deactivated.

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240507111214.3519800-1-lukma@denx.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>