meminfo cmd: Enable printing >=4GiB SDRAM sizes

gd->ram_size is stored as phys_size_t type which can be bigger than an
unsigned long on some architectures.  When using unsigned long type,
SDRAM of 4GiB or larger will not print the correct size, but using
phys_size_t will.

Signed-off-by: Andrew Bradford <andrew.bradford@kodakalaris.com>
diff --git a/common/cmd_mem.c b/common/cmd_mem.c
index 2e85d53..43c3fb6 100644
--- a/common/cmd_mem.c
+++ b/common/cmd_mem.c
@@ -1325,7 +1325,7 @@
 #endif
 
 #ifdef CONFIG_CMD_MEMINFO
-__weak void board_show_dram(ulong size)
+__weak void board_show_dram(phys_size_t size)
 {
 	puts("DRAM:  ");
 	print_size(size, "\n");