Eliminate special case id.inc/id.lds in favor of a configuration variable ID_SECTION_...

Eliminate special case id.inc/id.lds in favor of a configuration variable ID_SECTION_OFFSET
which is normally set to 0x10 (the current default) and set to 0x80 (the current alternative)
where necessary (if romstraps get in the way).
For Kconfig, the special case is set per southbridge (as these define the necessity for this
workaround), for newconfig it's added to each single board.

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Ronald G. Minnich <rminnich@gmail.com>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4962 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1