net: phy: air_en8811: add support for Airoha AN8811HB PHY

net: phy: air_en8811: add support for Airoha AN8811HB PHY

Add support for the Airoha AN8811HB 2.5 Gigabit PHY to the existing
en8811h driver. This PHY supports 10/100/1000/2500 Mbps speeds.

Update the driver to recognize the AN8811HB PHY ID and handle its
specific firmware loading requirements. The firmware loading mechanism
remains consistent with the existing implementation.

This driver is based on:
  - Linux upstream PHY subsystem (v7.0-rc1)
  - air_an8811hb v0.0.4 out-of-tree uboot driver written by
    "Lucien.Jheng <lucien.jheng@airoha.com>"

Tested on MT7987 RFB board.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=6f1769ec5892ac41d82e820d94dcdc68e904aa99
Link: https://patchwork.kernel.org/project/netdevbpf/patch/20260122071601.1057083-3-bjorn@mork.no/
Signed-off-by: Tommy Shih <tommy.shih@airoha.com>
Reviewed-by: Lucien.Jheng <lucienzx159@gmail.com>