PPC32: Page-align the data section of the boot wrapper.

This is needed for Open Firmware on older powermacs to be able to
load the wrapper.  Without this OF gives a "CLAIM failed" error.

arch/ppc/boot/ld.script

@@ -39,7 +39,7 @@ SECTIONS
   PROVIDE (etext = .);
 
   /* Read-write section, merged into data segment: */
-  . = ALIGN(8);
+  . = ALIGN(4096);
   .data    :
   {
     *(.data)