The USB HID driver had some static variables with keyboard state. This
moves them to the driver's instance, so multiple attached keyboards
don't effect each other.
Change-Id: I3f1ccfdea95062b443cebe510abf2f72fdeb1916
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1907
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Tested-by: build bot (Jenkins)