powerpc/mm: Use a helper for finding pte bits mapping I/O area

Use a helper instead of open coding with constants. A later patch will
drop the WIMG bits and use PowerISA 3.0 defines.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 9e0553e..ea60a24 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -253,7 +253,7 @@
 
 void __iomem * ioremap(phys_addr_t addr, unsigned long size)
 {
-	unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
+	unsigned long flags = pgprot_val(pgprot_noncached(__pgprot(0)));
 	void *caller = __builtin_return_address(0);
 
 	if (ppc_md.ioremap)
@@ -263,7 +263,7 @@
 
 void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
 {
-	unsigned long flags = _PAGE_NO_CACHE;
+	unsigned long flags = pgprot_val(pgprot_noncached_wc(__pgprot(0)));
 	void *caller = __builtin_return_address(0);
 
 	if (ppc_md.ioremap)