multimedia/libnymphcast: repair build

My home system is apparently slow enough that the parallel
mkdir and compilation-with-output-in-that-dir work out safely.
On the cluster, this leads to build failures. Use gmake feature
to add order-only dependencies to all the object files.

(See https://www.gnu.org/software/make/manual/html_node/Prerequisite-Types.html)

multimedia/nymphcastlib/Makefile

@@ -1,5 +1,6 @@
 PORTNAME=	NymphCastLib
 DISTVERSION=	v0.2.1
+PORTREVISION=	1
 CATEGORIES=	multimedia
 
 MAINTAINER=	adridg@FreeBSD.org

multimedia/nymphcastlib/files/patch-Makefile

@@ -0,0 +1,22 @@
+--- Makefile.orig	2024-12-03 20:49:22 UTC
++++ Makefile
+@@ -148,10 +148,10 @@ all: lib
+ 
+ lib: makedir lib/$(ARCH)$(OUTPUT).a lib/$(ARCH)$(LIBNAME)
+ 	
+-obj/static/$(ARCH)%.o: %.cpp
++obj/static/$(ARCH)%.o: %.cpp | makedir
+ 	$(CXX) -c -o $@ $< $(CXXFLAGS)
+ 	
+-obj/shared/$(ARCH)%.o: %.cpp
++obj/shared/$(ARCH)%.o: %.cpp | makedir
+ 	$(CXX) -c -o $@ $< $(CXXFLAGS) $(SHARED_FLAGS) $(LIBS)
+ 	
+ lib/$(ARCH)$(OUTPUT).a: $(OBJECTS)
+@@ -226,4 +226,4 @@ ifndef OS
+ endif
+ 
+ package:
+-	tar -C lib/$(ARCH) -cvzf lib/$(OUTPUT)-$(VERSION)-$(USYS)-$(UMCH).tar.gz $(OUTPUT).a $(OUTPUT).so.$(VERSION)
+\ No newline at end of file
++	tar -C lib/$(ARCH) -cvzf lib/$(OUTPUT)-$(VERSION)-$(USYS)-$(UMCH).tar.gz $(OUTPUT).a $(OUTPUT).so.$(VERSION)