commit ba9196d2 ("MIPS: Make DIEI support as a config option")
use CPU_HAS_DIEI to indicate whether di/ei is implemented correctly,
without this patch, "local_irq_disable" from entry.S in 3A1000
(with buggy di/ei) lose protection of commit e97c5b60 ("MIPS:
Make irqflags.h functions preempt-safe for non-mipsr2 cpus")

Fixes: ba9196d2 ("MIPS: Make DIEI support as a config option")
Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>