modpost: put modpost options before argument

The musl implementation of getopt stops looking for options after the
first non-option argument. Put the options before the non-option
argument so environments using musl can still build the kernel and
modules.

Fixes: f73edc89 ("kbuild: unify two modpost invocations")
Link: https://git.musl-libc.org/cgit/musl/tree/src/misc/getopt.c?h=dc9285ad1dc19349c407072cc48ba70dab86de45#n44


Signed-off-by: Richard Acayan <mailingradian@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>