[ARM] 3576/1: netX: board support for NXEB500HMI development board

Patch from Sascha Hauer

This patch adds the board specific code for the Hilscher NXEB500HMI
development board.

Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>