fix(zephyr): Add os_nanosleep impleemntation for POSIX platform

Author: lucasAbadFr

core/shared/platform/common/posix/posix_sleep.c

@@ -6,6 +6,7 @@
 #include <time.h>
 
 #include "platform_api_extension.h"
+#include "libc_errno.h"
 
 int
 os_usleep(uint32 usec)
@@ -18,3 +19,13 @@ os_usleep(uint32 usec)
     ret = nanosleep(&ts, NULL);
     return ret == 0 ? 0 : -1;
 }
+
+__wasi_errno_t
+os_nanosleep(os_timespec *req, os_timespec *rem)
+{
+    int ret;
+
+    ret = nanosleep(req, rem);
+
+    return convert_errno(ret);
+}