sunxi: DRAM: fix H3 DRAM size display on aarch64

Fix the output of the DRAM size on AArch64 SPLs.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NJagan Teki <jagan@openedev.com>

arch/arm/mach-sunxi/dram_sun8i_h3.c

@@ -664,6 +664,6 @@ unsigned long sunxi_dram_init(void)
 	mctl_auto_detect_dram_size(&para);
 	mctl_set_cr(&para);
 
-	return (1 << (para.row_bits + 3)) * para.page_size *
+	return (1UL << (para.row_bits + 3)) * para.page_size *
 						(para.dual_rank ? 2 : 1);
 }