PPC32: fix compile error by removing extraneous declarations (ppc_ksyms.c)

arch/ppc/kernel/ppc_ksyms.c

@@ -77,10 +77,6 @@ extern unsigned char __res[];
 
 extern unsigned long mm_ptov (unsigned long paddr);
 
-extern void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle);
-extern void consistent_free(void *vaddr);
-extern void consistent_sync(void *vaddr, size_t size, int direction);
-
 EXPORT_SYMBOL(clear_page);
 EXPORT_SYMBOL(do_signal);
 EXPORT_SYMBOL(do_syscall_trace);