mfd: stmpe: Add OF match table

The Documentation/devicetree/bindings/mfd/stmpe.txt DT binding doc lists
"st,stmpe[610|801|811|1601|2401|2403]" as valid compatible strings but
the corresponding driver does not have an OF match table. Add the table
to the driver so the SPI core can do an OF style match.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>