USB: Chipidea: add unified ci13xxx_{add,remove}_device for platform drivers

Platform drivers do the similar things to add/remove ci13xxx device, so
create a unified one.

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>