'xfreerdp /sound ...' and more importantly remmina configurations with
the GUI knob set to local sound will both use the "fake" backend by default.

'xfreerdp /sound:sys:sndio ...' and "sys:sndio" added as parameter in
remmina fix sound, but that takes a little digging (remmina's GUi tooltip
does not mention sndio).

As per xfreerdp(1):
     /sound[:[sys:sys,][dev:dev,][format:format,][rate:rate,][channel:channel,][latency:latency,][quality:quality]],
     /audio[:[sys:sys,][dev:dev,][format:format,][rate:rate,][channel:channel,][latency:latency,][quality:quality]]
            Audio output (sound)

The patch only defaults to sndio if exactly "/sound" was used, i.e.
any "/sound:..." invocation has the same effect as before.

I'm new to RDP from OpenBSD and thought sndio would be a saner default.

Feedback? Objection? OK?

Index: Makefile
===================================================================
RCS file: /cvs/ports/x11/freerdp/Makefile,v
diff -u -p -r1.67 Makefile
--- Makefile	27 Sep 2023 20:37:05 -0000	1.67
+++ Makefile	2 Feb 2024 05:07:24 -0000
@@ -2,6 +2,7 @@ COMMENT =		client for Microsoft RDP (rem
 DISTNAME =		freerdp-2.11.2
 DPB_PROPERTIES =	parallel
 CATEGORIES =		x11 net
+REVISION =		0
 
 SHARED_LIBS +=  freerdp-client2           1.1
 SHARED_LIBS +=  freerdp2                  3.0
Index: patches/patch-channels_rdpsnd_client_rdpsnd_main_c
===================================================================
RCS file: patches/patch-channels_rdpsnd_client_rdpsnd_main_c
diff -N patches/patch-channels_rdpsnd_client_rdpsnd_main_c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-channels_rdpsnd_client_rdpsnd_main_c	2 Feb 2024 05:57:05 -0000
@@ -0,0 +1,15 @@
+Default /sound (without parameters) to :sys:sndio
+
+Index: channels/rdpsnd/client/rdpsnd_main.c
+--- channels/rdpsnd/client/rdpsnd_main.c.orig
++++ channels/rdpsnd/client/rdpsnd_main.c
+@@ -966,7 +966,8 @@ static UINT rdpsnd_process_addin_args(rdpsndPlugin* rd
+ 			}
+ 			CommandLineSwitchEnd(arg)
+ 		} while ((arg = CommandLineFindNextArgumentA(arg)) != NULL);
+-	}
++	} else
++		rdpsnd_set_subsystem(rdpsnd, "sndio");	/* default to sndio(7) not fake backend */
+ 
+ 	return CHANNEL_RC_OK;
+ }