mach-ux500: add ST-UIB platform data

The ST-UIB contains a matrix keypad interfaced with the
STMPE1601 port expander and a ROHM BU2101 touch panel.

Signed-off-by: Sundar Iyer <sundar.iyer@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>