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-mvebu/arm64-common.c b/arch/arm/mach-mvebu/arm64-common.c
index d3a9573..4c67f1a 100644
--- a/arch/arm/mach-mvebu/arm64-common.c
+++ b/arch/arm/mach-mvebu/arm64-common.c
@@ -30,7 +30,7 @@
  */
 #define USABLE_RAM_SIZE		0x80000000ULL
 
-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)
 {
 	unsigned long top = CFG_SYS_SDRAM_BASE + min(gd->ram_size, USABLE_RAM_SIZE);