ARM: dts: imx6sx: add missing cells and move nodes

ARM: dts: imx6sx: add missing cells and move nodes

This fix below compilation warnings by,
1) Moving the sub nodes to regulator node.
2) Added address-cells and size-cells in regulator node.

Warning (reg_format): /regulator@1:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)
Warning (reg_format): /regulator@2:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)
Warning (reg_format): /regulator@3:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)
Warning (reg_format): /regulator@7:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)
Warning (reg_format): /regulator@9:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)
Warning (reg_format): /regulator@10:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)

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