headers: fix linux/mod_devicetable.h inclusions

A couple of drivers produced build errors after the mod_devicetable.h
header was split out from the platform_device one, e.g.

drivers/media/platform/davinci/vpbe_osd.c:42:40: error: array type has incomplete element type 'struct platform_device_id'
drivers/media/platform/davinci/vpbe_venc.c:42:40: error: array type has incomplete element type 'struct platform_device_id'

This adds the inclusion where needed.

Fixes: ac316725 ("headers: separate linux/mod_devicetable.h from linux/platform_device.h")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>