With multiboard support the compiletime generated BOARDINFO string
gets more and more meaningless. This removes it from Kconfig and
replaces it with a variable that can be set at boardlevel.

Also many boards have a standard setting for the hostname in the
environment. This patch also moves the standard to C code by calling
barebox_set_hostname().

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Udpate dhcp with it too.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

A look into "arch/arm/boards/" offers various boards starting with the
vendor's name in their directory name (like 'eukrea' and 'freescale').
This patch does the same for the currently existing FriendlyARM board
Mini2440.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>