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/board/menlo/m53menlo/m53menlo.c b/board/menlo/m53menlo/m53menlo.c
index ca3b81c..b8dffb0 100644
--- a/board/menlo/m53menlo/m53menlo.c
+++ b/board/menlo/m53menlo/m53menlo.c
@@ -42,7 +42,7 @@
 
 static u32 mx53_dram_size[2];
 
-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)
 {
 	/*
 	 * WARNING: We must override get_effective_memsize() function here