cmd: bdinfo: introduce bdinfo_print_size() helper

cmd: bdinfo: introduce bdinfo_print_size() helper

Add bdinfo_print_size() helper to display size variables (such as cache
sizes) in bdinfo format. The size is printed as "xxx Bytes", "xxx KiB",
"xxx MiB", "xxx GiB", etc as needed;

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Ovidiu Panait <ovpanait@gmail.com>
Reviewed-by: Jason Liu <jason.hui.liu@nxp.com>
Link: https://lore.kernel.org/r/20220829170205.1274484-3-ovpanait@gmail.com
Signed-off-by: Michal Simek <michal.simek@amd.com>