[][Add MT7986 upstream thermal driver]

[Description]
Add MT7986 upstream thermal driver.
Currently the driver supports thermal V1, V2 and V3.
	- V1 : MT8173, MT8183, MT2701, MT2712
	- V2 : MT7622
	- V3 : MT7986

[How-to]
The way to obtain current temperature.
	- cat /sys/class/thermal/thermal_zone0/temp

[Release-log]
N/A

Change-Id: I2ad368cd2b3937fecf7c71260605ca060e2cf2ee
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/4638655
4 files changed