ps1/heap.c: bump heap size

src/gfx/ps1/src/heap.c

@@ -13,7 +13,7 @@ void gfx_swapheap(void)
 
 static void *get_element(const size_t sz)
 {
-    enum {HEAP_SZ = 5120, N_HEAPS = 2};
+    enum {HEAP_SZ = 6144, N_HEAPS = 2};
     static char heaps[N_HEAPS][HEAP_SZ];
     const size_t new_sz = heap_i + sz;
     void *ret = NULL;