[][Add TRNG support for MT7986]

[Description]
Add trng for MT7986.

1. Add compatible for mt7986
2. Fix mtk_rng_wait_ready() function

[Release-log]
N/A

Change-Id: Id8a5c2e5d5dedf8aeb1e86dbd683d9b0f13a04a4
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/4704459
1 file changed