ARM: dts: imx6qdl-kontron-samx6i: fix I2C_PM scl pin

Use the correct pin for the i2c scl signal else we can't access the
SoM eeprom.

Fixes: 2a51f9da ("ARM: dts: imx6qdl-kontron-samx6i: Add iMX6-based Kontron SMARC-sAMX6i module")
Signed-off-by: Bernd Bauer <bernd.bauer@anton-paar.com>
[m.felsch@pengutronix.de: Adapt commit message]
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>