3ds: 3ds port sources. First set of two

This commit adds changes to the original rockbox sources.

Note: the port files, functions, folders, etc., will be referred
to as 'ctru' to avoid using the Nintendo name elsewhere.

Change-Id: I0e2d3d4d2a75bd45ea67dc3452eb8d5487cf1f5a

apps/SOURCES

@@ -305,4 +305,6 @@ keymaps/keymap-echor1.c
 keymaps/keymap-surfansf28.c
 #elif CONFIG_KEYPAD == RG_NANO_PAD
 keymaps/keymap-rgnano.c
+#elif CONFIG_KEYPAD == CTRU_PAD
+keymaps/keymap-ctru.c
 #endif

apps/tree.c

@@ -565,7 +565,11 @@ void resume_directory(const char *dir)
 
 /* Returns the current working directory and also writes cwd to buf if
    non-NULL.  In case of error, returns NULL. */
+#ifdef CTRU
+char *__wrap_getcwd(char *buf, getcwd_size_t size)
+#else
 char *getcwd(char *buf, getcwd_size_t size)
+#endif
 {
     if (!buf)
         return tc.currdir;

apps/tree.h

@@ -128,7 +128,12 @@ void tree_unlock_cache(struct tree_context *t);
 #else
 #define getcwd_size_t size_t
 #endif
+#ifdef CTRU
+/* devkitarm already defines getcwd */
+char *__wrap_getcwd(char *buf, getcwd_size_t size);
+#else
 char *getcwd(char *buf, getcwd_size_t size);
+#endif
 void reload_directory(void);
 bool check_rockboxdir(void);
 struct tree_context* tree_get_context(void);