Move the sprom parsing from nvram into sprom.c. There are all values
needed for sprom version 1 to 9 read from nvram and there are more
sanity checks added. This is based on the sprom parsing in the open
source part of the Broadcom SDK.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>