net: phy: broadcom: Rename LED registers

These registers are common to most PHYs and are not specific to the
BCM5482, renamed the constants accordingly, no functional change.

Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>