arm: vf610: Add IOMUX support for Vybrid VF610

arm: vf610: Add IOMUX support for Vybrid VF610

This patch adds the IOMUX support for Vybrid VF610 platform.

There is a little difference for IOMUXC module between VF610 and i.MX
platform, the muxmode and pad configuration share one 32bit register on
VF610, but they are two independent registers on I.MX platform. A
CONFIG_IOMUX_SHARE_CONFIG_REG was introduced to fit this difference.

Signed-off-by: Alison Wang <[email protected]>
Acked-by: Stefano Babic <[email protected]>
Reviewed-by: Benoît Thébaudeau <[email protected]>