net: spacemit: Check netif_running() in emac_set_pauseparam()

net: spacemit: Check netif_running() in emac_set_pauseparam()

Currently, emac_set_pauseparam() will oops if userspace calls it while
the interface is not up, because phydev is NULL, but it is still
accessed in emac_set_fc() and emac_set_fc_autoneg().

Check for netif_running(dev) in emac_set_pauseparam() before proceeding.

Fixes: bfec6d7f2001 ("net: spacemit: Add K1 Ethernet MAC")
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251103-k1-ethernet-remove-fc-v3-1-2083770cd282@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>