LoongArch: Select HAVE_POSIX_CPU_TIMERS_TASK_WORK

Move POSIX CPU timer expiry and signal delivery into task context to
allow PREEMPT_RT setups to coexist with KVM.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/Kconfig

@@ -155,6 +155,7 @@ config LOONGARCH
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select HAVE_PREEMPT_DYNAMIC_KEY
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC