Input: remove unneeded version.h includes

It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/input/.
This patch removes them.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>