arm64: dts: imx8ulp: update gpio node

The i.MX8ULP GPIO supports two interrupts and one register base,
the current fsl,imx7ulp-gpio compatible could work for i.MX8ULP in
gpio-vf610.c driver, it is based on the base address are splited
into two with offset added in device tree node. Now following
hardware design, using one register base in device tree node.

This may break users who use compatible fsl,imx7ulp-gpio to enable
i.MX8ULP GPIO.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>