[coreboot] [PATCH]Remove {HAVE, USE}_{FALLBACK, FAILOVER}_* and its uses

[Patrick Georgi]

Hi,

attached patch removes the remaining uses of
HAVE_FAILOVER_BOOT
HAVE_FALLBACK_BOOT
USE_FAILOVER_IMAGE
USE_FALLBACK_IMAGE

This effort (which is finalized by this patch) should simplify the code
flow, so it's easier to figure out what's going on and where.
It mightalso fix some boards that had obsolete assumptions about the
config flags above.

The change is abuild tested, but not boot tested, I hope I didn't break
anything.

Signed-off-by: Patrick Georgi