common: memtop: Fix the return type for find_ram_top

As the return type is "int" for find_ram_top() function and
returning the "base" which is of phys_addr_t is breaking when the
"base" address is 64-bit. So fix this by updating the return type as
phys_addr_t.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Acked-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Link: https://lore.kernel.org/r/20241220030742.1745984-1-venkatesh.abbarapu@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/common/memtop.c b/common/memtop.c
index 841d89e..bff27d8 100644
--- a/common/memtop.c
+++ b/common/memtop.c
@@ -121,8 +121,8 @@
 	return (i < mem_rgn->count) ? i : -1;
 }
 
-static int find_ram_top(struct mem_region *free_mem,
-			struct mem_region *reserved_mem, phys_size_t size)
+static phys_addr_t find_ram_top(struct mem_region *free_mem,
+				struct mem_region *reserved_mem, phys_size_t size)
 {
 	long i, rgn;
 	phys_addr_t base = 0;