net: phy: qca807x: add support for configurable LED

QCA8072/5 have up to 2 LEDs attached for PHY.

LEDs can be configured to be ON/hw blink or be set to HW control.

Hw blink mode is set to blink at 4Hz or 250ms.

PHY can support both copper (TP) or fiber (FIBRE) kind and supports
different HW control modes based on the port type.

HW control modes supported for netdev trigger for copper ports are:
- LINK_10
- LINK_100
- LINK_1000
- TX
- RX
- FULL_DUPLEX
- HALF_DUPLEX

HW control modes supported for netdev trigger for fiber ports are:
- LINK_100
- LINK_1000
- TX
- RX
- FULL_DUPLEX
- HALF_DUPLEX

LED support conflicts with GPIO controller feature and must be disabled
if gpio-controller is used for the PHY.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>