Mercusys MR60X support

For Developers
7

from quick investigation:

MR60X v1: MediaTek MT7621 (basic.config in MR60X-gpl/build/)
MR60X v2: Realtek RTL8197F? (kernel data in MR60Xv2-up-ver1-0-4-P1[20230529-rel42385]_2023-05-29_11.48.03.bin)