add copyright stuff to substantially changed files

platform/common/host_dasm.c

@@ -1,3 +1,7 @@
+/*
+ * DRC host disassembler interface for MIPS/ARM32 for use without binutils
+ * (C) kub, 2018,2019
+ */
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>

platform/common/menu_pico.c

@@ -923,7 +923,8 @@ static void draw_frame_credits(void)
 }
 
 static const char credits[] =
-	"PicoDrive v" VERSION " (c) notaz, 2006-2013\n\n\n"
+	"PicoDrive v" VERSION "\n"
+	"(c) notaz, 2006-2013; irixxxx, 2018-2020\n\n"
 	"Credits:\n"
 	"fDave: initial code\n"
 #ifdef EMU_C68K