[PATCH] cobalt/rtdm: add explicit declaration of function rtdm_nrtsig_init

[hongzha1 via Xenomai]

fix implicit declaration of function error when compile other cobalt
drivers calling rtdm_nrtsig_init

---
this patch is for wip/dovetail branch

Signed-off-by: hongzha1 <hongzhan.c...@intel.com>

diff --git a/include/cobalt/kernel/rtdm/driver.h 
b/include/cobalt/kernel/rtdm/driver.h
index 2f10fa797..70bea02be 100644
--- a/include/cobalt/kernel/rtdm/driver.h
+++ b/include/cobalt/kernel/rtdm/driver.h
@@ -902,6 +902,9 @@ struct rtdm_nrtsig {
        struct irq_work irq_work;
 };
 
+int rtdm_nrtsig_init(rtdm_nrtsig_t *nrt_sig, rtdm_nrtsig_handler_t handler,
+               void *arg);
+
 void rtdm_schedule_nrt_work(struct work_struct *lostage_work);
 /** @} rtdm_nrtsignal */
 
-- 
2.17.1