dipswitch.c: Rename src and header file

- (non function-changing update) just for consistency, append "libretro_" to source file to be consistent with new core option file

Makefile.common

@@ -57,4 +57,4 @@ endif
 SOURCES_C += \
 				 $(CORE_DIR)/ines.c \
 				 $(CORE_DIR)/unif.c $(CORE_DIR)/x6502.c \
-				 $(CORE_DIR)/drivers/libretro/dipswitch.c
+				 $(CORE_DIR)/drivers/libretro/libretro_dipswitch.c

src/drivers/libretro/libretro.c

@@ -29,7 +29,7 @@
 #endif
 
 #include "libretro-common/include/streams/memory_stream.h"
-#include "dipswitch.h"
+#include "libretro_dipswitch.h"
 #include "libretro_core_options.h"
 
 #define MAX_PLAYERS 4 /* max supported players */

src/drivers/libretro/libretro_dipswitch.c

@@ -9,7 +9,7 @@
 #include "../../driver.h"
 #include "../../cart.h"
 
-#include "dipswitch.h"
+#include "libretro_dipswitch.h"
 
 extern CartInfo iNESCart;