ARM: dts: imx6: phyFLEX: Set correct interrupt for pmic

The PMIC interrupt was changed from modul revision 1 to 2. Revision 1 was
declared as a prototype and is not in series by any customers.

Signed-off-by: Christian Hemp <c.hemp@phytec.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>