uboot-imx

imx: mx51_efikamx/sb: Convert to iomux-v3

There is no change of behavior, except for older silicon revisions for which
support is removed.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Tested-by: Matt Sealey <matt@genesi-usa.com>