powerpc/8xx: move setup_initial_memory_limit() into 8xx_mmu.c

Now we have a 8xx specific .c file for that so put it in there
as other powerpc variants do

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
diff --git a/arch/powerpc/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c
index 2d42745..a84f5eb 100644
--- a/arch/powerpc/mm/8xx_mmu.c
+++ b/arch/powerpc/mm/8xx_mmu.c
@@ -81,3 +81,20 @@
 
 	return mapped;
 }
+
+void setup_initial_memory_limit(phys_addr_t first_memblock_base,
+				phys_addr_t first_memblock_size)
+{
+	/* We don't currently support the first MEMBLOCK not mapping 0
+	 * physical on those processors
+	 */
+	BUG_ON(first_memblock_base != 0);
+
+#ifdef CONFIG_PIN_TLB
+	/* 8xx can only access 24MB at the moment */
+	memblock_set_current_limit(min_t(u64, first_memblock_size, 0x01800000));
+#else
+	/* 8xx can only access 8MB at the moment */
+	memblock_set_current_limit(min_t(u64, first_memblock_size, 0x00800000));
+#endif
+}