ARM: defconfig: select the right SX150X driver

The SX150X GPIO expander has been moved to pin control and
its Kconfig symbol has been renamed. We used to have a paper-over
thing in Kconfig but it was causing circular dependencies so
I have had to kill it off. Select the right driver instead.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>