ARM: dts: imx6qp.dtsi: update node naming standards for 4.19

ARM: dts: imx6qp.dtsi: update node naming standards for 4.19

Fix below compilation warnings by adhering to 4.19 node naming standards.

Warning (reg_format): /soc/aips-bus@02100000/pre@021c8000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 1)
Warning (reg_format): /soc/aips-bus@02100000/pre@021c9000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 1)
Warning (reg_format): /soc/aips-bus@02100000/pre@021ca000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 1)
Warning (reg_format): /soc/aips-bus@02100000/pre@021cb000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 1)
Warning (reg_format): /soc/aips-bus@02100000/prg@021cc000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 1)
Warning (reg_format): /soc/aips-bus@02100000/prg@021cd000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 1)

Signed-off-by: Arulpandiyan Vadivel <arulpandiyan_vadivel@mentor.com>