fix some warnings from psp builds (missing includes.)

src/audio/psp/SDL_pspaudio.c

@@ -25,6 +25,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <malloc.h> /* memalign() */
 
 #include "SDL_audio.h"
 #include "SDL_error.h"

src/video/psp/SDL_pspevents.c

@@ -34,6 +34,7 @@
 #include "SDL_keyboard.h"
 #include "../../thread/SDL_systhread.h"
 #include <psphprm.h>
+#include <pspthreadman.h>
 
 #ifdef PSPIRKEYB
 #include <pspirkeyb.h>