dts:exynos:update pinctrl size-cells and fix child regs

dts:exynos:update pinctrl size-cells and fix child regs

This change is required to avoid warnings about invalid
size-cells defined in device-tree pinctrl nodes for Exynos.

Tested on:
- Odroid U3
- Odroid XU3

Signed-off-by: Przemyslaw Marczak <[email protected]>
Cc: Stefan Roese <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Stephen Warren <[email protected]>
Cc: Stephen Warren <[email protected]>
Tested-by: Simon Glass <[email protected]>
Acked-by: Simon Glass <[email protected]>
Acked-by: Minkyu Kang <[email protected]>