net: phy: ksz90x1: Handle ksz9131 LED errata

net: phy: ksz90x1: Handle ksz9131 LED errata

Micrel KSZ9131 PHY LED behavior is not correct when configured in
Individual Mode, LED1 (Activity LED) is in the ON state when there is
no-link.

Workaround this by setting bit 9 of register 0x1e after verifying that
the LED configuration is Individual Mode.

This issue is described in KSZ9131RNX Silicon Errata DS80000693B [*]
and according to that it will not be corrected in a future silicon
revision.

[*] https://ww1.microchip.com/downloads/en/DeviceDoc/KSZ9131RNX-Silicon-Errata-and-Data-Sheet-Clarification-80000863B.pdf

Based on commit 0316c7e66bbd in the Linux kernel.

Tested-by: Quentin Schulz <quentin.schulz@cherry.de> # RK3588 Tiger
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>