common: introduce factory_info command

common: introduce factory_info command

This patch introduces factory_info command to save/load
the factory information such as s/n, mac address.
The command supports mmc interface to save/load data into
mmc device. Please refer below command usage.

"Factory Information commands",
"list - List factory information\n"
"factory_info load <interface> <device> <offset> <cnt>\n"
"        - Load factory information from the interface\n"
"factory_info save <interface> <device> <offset> <cnt>\n"
"        - Save factory information to the interface\n"
"factory_info read <entity name> - Read a value of entity name\n"
"factory_info write <entity name> <val> - Write a value of entity name\n"
"factory_info clean - Clean factioy information\n"

Change-Id: Ia1f4cebf264f6f573000d001fe24a6cc88c5a8e8
Signed-off-by: Chanho Park <chanho61.park@samsung.com>