support 4 partitions for arm odroid u3

support 4 partitions for arm odroid u3

This patch supports 4 partitions for arm odroid u3 which is reference
target of arm. Unlike tizen-2.2.1, we want to change partition maps of
arm target because platform.img/data.img/ums.img are really ambiguous from
developers. To clarify the partition name, we decide to change partition
names.

/boot: boot.img
/: rootfs.img
/opt: system-data.img
/opt/usr: user.img

Change-Id: I3208ee7404dcc6a5fd72c2e8af0fac67b7023af0
Signed-off-by: Chanho Park <chanho61.park@samsung.com>