Becuase the board select menu in arch/arm/Kconfig is too big,
move the KirkWood board select menu to kirkwood/Kconfig.
Consolidate also common settings (CONFIG_SYS_CPU="arm926ejs" and
CONFIG_SYS_SOC="kirkwood").
Signed-off-by: Masahiro Yamada
Acked-by: Prafulla Wadasdkar
Cc: Luka Perkov