[ARM] pxa/income: Add Income SBC support

This is support for custom design based on Toradex Colibri PXA270 CPU card.
Initial patch was by Pavel Revak.

[daniel - rebased the code to follow the module/board split]

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Pavel Revak <palo@bielyvlk.sk>
Cc: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>