[Maintenance] Move the value-first outw() variant to decomp.h

Not really PC-98-hardware-related, not really master.lib-related, so
yeah, that's really the best place for it.

Part of P0116, funded by [Anonymous] and Lmocinemod.

decomp.h

@@ -11,3 +11,10 @@
 // get the N versions.
 #define FLAGS_ZERO (_FLAGS & 0x40) /* JZ */
 // ----------------
+
+// Alternate version that sets the value first
+#define OUTW2(port, val) __asm { \
+	mov ax, val; \
+	mov dx, port; \
+	out dx, ax; \
+}

th01/hardware/egcscopy.c

@@ -1,9 +1,4 @@
-// Alternate version that sets the value first
-#define OUTW2(port, val) __asm { \
-	mov ax, val; \
-	mov dx, port; \
-	out dx, ax; \
-}
+#include "decomp.h"
 
 void pascal egc_start_copy(void)
 {