Remove volatile qualifier in get_ram_size() calls

Checkpatch.pl complains about the volatile qualifier in calls to
get_ram_size(). Remove this qualifier in the prototype and in the
calls where it is useless, and leave it only in the function body
where it is needed.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
diff --git a/board/karo/tx25/tx25.c b/board/karo/tx25/tx25.c
index 4088374..25b99e8 100644
--- a/board/karo/tx25/tx25.c
+++ b/board/karo/tx25/tx25.c
@@ -160,7 +160,7 @@
 int dram_init (void)
 {
 	/* dram_init must store complete ramsize in gd->ram_size */
-	gd->ram_size = get_ram_size((volatile void *)PHYS_SDRAM_1,
+	gd->ram_size = get_ram_size((void *)PHYS_SDRAM_1,
 				PHYS_SDRAM_1_SIZE);
 	return 0;
 }
@@ -168,11 +168,11 @@
 void dram_init_banksize(void)
 {
 	gd->bd->bi_dram[0].start = PHYS_SDRAM_1;
-	gd->bd->bi_dram[0].size = get_ram_size((volatile void *)PHYS_SDRAM_1,
+	gd->bd->bi_dram[0].size = get_ram_size((void *)PHYS_SDRAM_1,
 			PHYS_SDRAM_1_SIZE);
 #if CONFIG_NR_DRAM_BANKS > 1
 	gd->bd->bi_dram[1].start = PHYS_SDRAM_2;
-	gd->bd->bi_dram[1].size = get_ram_size((volatile void *)PHYS_SDRAM_2,
+	gd->bd->bi_dram[1].size = get_ram_size((void *)PHYS_SDRAM_2,
 			PHYS_SDRAM_2_SIZE);
 #else