sh: Fix the offset from P1SEG/P2SEG where we map RAM

We need to map the gap between 0x00000000 and __MEMORY_START in the PMB,
as well as RAM.

With this change my 7785LCR board can switch to 32bit MMU mode at
runtime.

Signed-off-by: Matt Fleming <[e-mail]>
Signed-off-by: Paul Mundt <[e-mail]>

arch/sh/mm/pmb.c

···
 int __uses_jump_to_uncached pmb_init(void)
 {
 	unsigned int i;
-	long size;
+	long size, ret;
 
 	jump_to_uncached();
 
···
 	 *	P1 - provides a cached window onto physical memory
 	 *	P2 - provides an uncached window onto physical memory
 	 */
-	size = pmb_remap(P2SEG, __MEMORY_START, __MEMORY_SIZE,
-			 PMB_WT | PMB_UB);
-	BUG_ON(size != __MEMORY_SIZE);
+	size = __MEMORY_START + __MEMORY_SIZE;
 
-	size = pmb_remap(P1SEG, __MEMORY_START, __MEMORY_SIZE, PMB_C);
-	BUG_ON(size != __MEMORY_SIZE);
+	ret = pmb_remap(P1SEG, 0x00000000, size, PMB_C);
+	BUG_ON(ret != size);
+
+	ret = pmb_remap(P2SEG, 0x00000000, size, PMB_WT | PMB_UB);
+	BUG_ON(ret != size);
 
 	ctrl_outl(0, PMB_IRMCR);