[][Update config to support mt7986 pwm fan]

[Description]
Add pwm fan kernel config

[Release-log]
N/A

Change-Id: Icb0d352821fb91108eb08f46f8bda8f1419f6f93
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6027381
1 file changed