Clearing obj-y, obj-m, obj-n, obj- in each Makefile is
a useless habit.
They are non-exported variables; therefore they are always empty
whenever descending into each subdirectory.
(Moreorver, obj-y and obj-m are also set to empty at the beginning
of scripts/Makefile.build)
Signed-off-by: Masahiro Yamada
Acked-by: Nicolas Ferre
Acked-by: Peter Foley
Acked-by: Linus Walleij
Signed-off-by: Michal Marek