ARM: exynos: add missing include of linux/module.h

After the restructuring of the module.h and init.h headers,
we now need to include this explicitly here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>