ARM: dts: omap3-igep0020: Add SMSC911x LAN chip support

The IGEPv2 board has an SMSC LAN9221i ethernet chip connected to
the OMAP3 processor though the General-Purpose Memory Controller.

This patch adds a device node for the ethernet chip as a GPMC child
and all its requirements (regulators, GPIO and pin muxs).

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
ARM: OMAP: gpmc: (HACK) explicitly call request_gpio for smsc IRQ-GPIO

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>