ENGR00266312 mx6dl: add i2c4 bus support for sabresd/auto, arm2 platforms

imx6dq have 3 i2c controllers and 5 ecspi,imx6dl have 4 i2c4
controllers and 4 ecspi. imx6dl i2c4 clock source is routed
from pll3 through to ecspi_root gate.

Add i2c4 bus support for sabresd/auto, and arm2 platforms.

Signed-off-by: Fugang Duan <B38611@freescale.com>