KCM: restore support for Solaris doors IPC mechanism (#379)

This patch restores support for the Solaris doors IPC mechanism, removed
from KCM when lib/ipc was added.

kcm/config.c

@@ -40,7 +40,6 @@ static const char *config_file;	/* location of kcm config file */
 
 size_t max_request = 0;		/* maximal size of a request */
 char *socket_path = NULL;
-char *door_path = NULL;
 
 static char *max_request_str;	/* `max_request' as a string */
 
@@ -123,12 +122,6 @@ static struct getargs args[] = {
 	"socket-path",		's', arg_string, &socket_path,
     	"path to kcm domain socket", "path"
     },
-#ifdef HAVE_DOOR_CREATE
-    {
-	"door-path",		's', arg_string, &door_path,
-    	"path to kcm door", "path"
-    },
-#endif
     {
 	"server",		'S', arg_string, &system_server,
     	"server to get system ticket for", "principal"