eth: bcmsysport: fix call balance of priv->clk handling routines

eth: bcmsysport: fix call balance of priv->clk handling routines

Check the return value of clk_prepare_enable to ensure that priv->clk has
been successfully enabled.

If priv->clk was not enabled during bcm_sysport_probe, bcm_sysport_resume,
or bcm_sysport_open, it must not be disabled in any subsequent execution
paths.

Fixes: 31bc72d97656 ("net: systemport: fetch and use clock resources")
Signed-off-by: Vitalii Mordan <mordan@ispras.ru>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20241227123007.2333397-1-mordan@ispras.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>