ARM: ux500: fix spi2 pin group

GPIO216_AG12 is configured as a gpio for SPI2, so select
the spi2_oc1_2 pin group instead of spi2_oc1_1

Signed-off-by: Patrice Chotard <patrice.chotard@stericsson.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>