gpio: max7300: Fix trivial typo in Kconfig help text

max7301 is controlled through SPI interface which means another driver.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>