ARM: constify machine_desc structure uses

struct machine_desc records are defined everywhere as a 'const'
structure, but unfortuantely it loses its const-ness through the use of
linker magic - the symbols which surround the section are not declared
const so it becomes possible not to use 'const' for pointers to these
const structures.

Let's fix this oversight - all pointers to these structures should be
marked const too.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 15225d8..2958e74 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -231,7 +231,7 @@
 }
 #endif
 
-void __init setup_dma_zone(struct machine_desc *mdesc)
+void __init setup_dma_zone(const struct machine_desc *mdesc)
 {
 #ifdef CONFIG_ZONE_DMA
 	if (mdesc->dma_zone_size) {
@@ -335,7 +335,8 @@
 	return phys;
 }
 
-void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
+void __init arm_memblock_init(struct meminfo *mi,
+	const struct machine_desc *mdesc)
 {
 	int i;