common: return type board_get_usable_ram_top

board_get_usable_ram_top() returns a physical address that is stored in
gd->ram_top. The return type of the function should be phys_addr_t like the
current type of gd->ram_top.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/arch/arm/mach-tegra/board2.c b/arch/arm/mach-tegra/board2.c
index 0df1836..981768b 100644
--- a/arch/arm/mach-tegra/board2.c
+++ b/arch/arm/mach-tegra/board2.c
@@ -403,7 +403,7 @@
  * This function is called before dram_init_banksize(), so we can't simply
  * return gd->bd->bi_dram[1].start + gd->bd->bi_dram[1].size.
  */
-phys_size_t board_get_usable_ram_top(phys_size_t total_size)
+phys_addr_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	ulong ram_top;