sh: define TASK_UNMAPPED_BASE as a page aligned constant

b4265f12340f809447b9a48055e88c444b480c89
(mm: use vm_unmapped_area() on sh architecture)
broke sh boot. This patch define TASK_UNMAPPED_BASE
as a page aligned constant to solve this issue.
Special thanks to Michel

Acked-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/processor_32.h

@@ -39,7 +39,7 @@
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */
-#define TASK_UNMAPPED_BASE	(TASK_SIZE / 3)
+#define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)
 
 /*
  * Bit of SR register

arch/sh/include/asm/processor_64.h

@@ -47,7 +47,7 @@ pc; })
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */
-#define TASK_UNMAPPED_BASE	(TASK_SIZE / 3)
+#define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)
 
 /*
  * Bit of SR register