ARM: dts: imx6ul-pico-hobbit: Fix the 'interrupts' property

The 'interrupts' property has an extra cell by mistake.

Fix this, so that the following build warning is gone:

 DTC     arch/arm/boot/dts/imx6ul-pico-hobbit.dtb
arch/arm/boot/dts/imx6ul-pico-hobbit.dtb: Warning (interrupts_property): interrupts size is (12), expected multiple of 8 in /soc/aips-bus@2000000/ethernet@20b4000/mdio/ethernet-phy@1

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>