max3110 sanity check a register

max3110 sanity check a register

MAX3111 is the SPI/UART IC installed on the MRST SPI Port Card as a serial
debug goal, and the SPI Port Card will be frequently mounted and unmounted
from the main board by developers depending whether debug serial is
required or not.

As the MAX3111 has no subvendor or product id registers available, the patch
will try to access one register to decide if this IC is present or not.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>