The PM timer is availiable in case of ACPI is unusable or blacklisted.
So let's enable it as a fallback timer when APIC timer goes wrong.
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Reviewed-by: NDust Li <dust.li@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>