Input: bcm5974 - Add support for newer MacBookPro8,2

New MacBook Pro devices reporting product name MacBookPro8,2 come with
newer/higher resolution touchpads than others with the same product
name with USB ID 05ac:0252. This patch adds support for these devices.

Signed-off-by: Andrew Drake <adrake@adrake.org>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>