Codebase is meant to be gnu89, but this was only enforced starting
with bc4840e98b94 ("kbuild: add -Wmissing-prototypes and -std=gnu89
to KBUILD_HOSTCFLAGS"). Since then, use of this macro would yield a
compile error, because of the initialization inside the for-loop,
which is a C99 feature. There hasn't been any users for the macro
since it was added in 2016, thus drop it.

This reverts commit d5f9415.

Cc: Trent Piepho <tpiepho@kymetacorp.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>