ODROID: Change the prefix of image file to 'odroid-*'

This patch changes the prefix of image file to start with 'odroid-*'.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
ODROID: remove --bootstrap-flavour option

'--bootstrap-flavour' option is deprecated

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
ODROID: remove BUILD_NUMBER as default

$(BUILD_NUMBER) is removed on image name as default, will be added if it is
defined. Jenkins manage $(BUILD_NUMBER) internally, so it will be added when
Jenkins runs.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
ODROID: change default user and groups

This patch is to change default user and groups to 'odroid' instead of
'linaro'.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
ODROID: change hostname

The hostname is changed to 'odroid-ubuntu-desktop'.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
ODROID: change default login account

Signed-off-by: Dongjin Kim <tobetter@gmail.com>