[PATCH] phy: adin: add readext and writeext support for mdio cmd

[Marek Vasut]

On 7/11/23 23:59, Nate Drude wrote:
> The adin phy has extended registers that can be accessed using
> adin_ext_read and adin_ext_write. These registers can be read directly
> using the mdio command using readext and writext. For example:
> 
>      => mdio rx ethernet at 428a0000 0xff23
>      Reading from bus ethernet at 428a0000
>      PHY at address 0:
>      65315 - 0xe01
> 
> Signed-off-by: Nate Drude <nate.d at variscite.com>

Reviewed-by: Marek Vasut <marek.vasut+renesas at mailbox.org>