osu: Add an option to print all board params

osu: Add an option to print all board params

Add an option called --get-all-board-param to print all board parameters.
It will show all board parameter with instruction 'osu --get-all-board-param'.
It is the option for users who want to know all board parameters at once.
If the user want to know just one board parameter, then use 'osu --get-board-param'.
If the user want to know all board parameters, then use 'osu --get-all-board-param'

Example of the result of 'osu --get-all-board-param':
boot-mode: normal
current-partition: a
partition-ab-cloned: 1
partition-status: a: ok
partition-status: b: ok
upgrade-progress-status: 0
upgrade-state: standby
upgrade-type: offline

Change-Id: I41361b473a24f855af27a04560d74d74824562e3
Signed-off-by: Unsung Lee <unsung.lee@samsung.com>