Small cleanup to how macros are defined for SDL OSD

scripts/src/osd/sdl_cfg.lua

@@ -111,7 +111,6 @@ end
 
 if _OPTIONS["targetos"]=="windows" then
 	defines {
-		"SDLMAME_WIN32",
 		"UNICODE",
 		"_UNICODE",
 		"USE_QTDEBUG=" .. USE_QT,
@@ -147,21 +146,11 @@ elseif _OPTIONS["targetos"]=="macosx" then
 		"SDLMAME_NET_PCAP",
 	}
 elseif _OPTIONS["targetos"]=="freebsd" then
-	defines {
-		"NO_AFFINITY_NP",
-	}
 	buildoptions {
 		-- /usr/local/include is not considered a system include director on FreeBSD.  GL.h resides there and throws warnings
 		"-isystem /usr/local/include",
 	}
-elseif _OPTIONS["targetos"]=="solaris" then
-	defines {
-		"NO_AFFINITY_NP",
-	}
 elseif _OPTIONS["targetos"]=="os2" then
-	defines {
-		"SDLMAME_OS2",
-	}
 	buildoptions {
 		string.gsub(os.outputof(sdlconfigcmd() .. " --cflags"), '[\r\n]+', ' '),
 	}

src/osd/sdl/sdlmain.c

@@ -400,7 +400,6 @@ static void defines_verbose(void)
 	MACRO_VERBOSE(NO_DEBUGBER);
 	MACRO_VERBOSE(BIGENDIAN);
 	MACRO_VERBOSE(CPP_COMPILE);
-	MACRO_VERBOSE(DISTRO);
 	MACRO_VERBOSE(SYNC_IMPLEMENTATION);
 	osd_printf_verbose("\n");
 	osd_printf_verbose("SDL/OpenGL defines: ");

src/osd/sdl/sdlprefix.h

@@ -14,7 +14,8 @@
 //============================================================
 
 /* Only problems ... */
-#ifdef SDLMAME_WIN32
+#if defined(_WIN32)
+#define SDLMAME_WIN32
 #define _SDL_main_h
 #endif
 
@@ -27,6 +28,7 @@
 
 #if defined(__sun__) && defined(__svr4__)
 #define SDLMAME_SOLARIS 1
+#define NO_AFFINITY_NP 1
 //#undef _XOPEN_SOURCE
 //#undef _XOPEN_VERSION
 //#undef _XOPEN_SOURCE_EXTENDED
@@ -45,6 +47,7 @@
 
 #elif defined(__FreeBSD__)
 #define SDLMAME_FREEBSD 1
+#define NO_AFFINITY_NP 1
 #elif defined(__DragonFly__)
 #define SDLMAME_DRAGONFLY 1
 #elif defined(__OpenBSD__)
@@ -57,6 +60,10 @@
 #define SDLMAME_BSD 1
 #endif
 
+#if defined(__OS2__)
+#define SDLMAME_OS2 1
+#endif
+
 #if defined(__HAIKU__)
 #define SDLMAME_HAIKU 1
 #define SDLMAME_NO64BITIO 1