lib: utils/timer: mtimer: add T-Head C9xx CLINT compatible

As we already added the quirk for lacking mtime register to MTIMER
driver, add T-Head C9xx CLINT compatible to it and wire the quirk.

Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: Anup Patel <anup@brainfault.org>