[coreboot] Config.lb includes

[Carl-Daniel Hailfinger]

We have 14 Config.lb files in the mainboard dir of our tree which all
contain exactly the same first section (comments and whitespace are
vastly different, but the code is identical):

Ron, you wrote that Config.lb can do include statements. I didn't find
any examples, but maybe I just looked at the wrong part of the code.
Tell me how to use the include statements and I'll refactor the section
below out of lots of boards.
--------------------------------------
##
## Compute the location and size of where this firmware image
## (coreboot plus bootloader) will live in the boot rom chip.
##
if USE_FAILOVER_IMAGE
        default ROM_SECTION_SIZE   = FAILOVER_SIZE
        default ROM_SECTION_OFFSET = ( ROM_SIZE - FAILOVER_SIZE )
else
    if USE_FALLBACK_IMAGE
        default ROM_SECTION_SIZE   = FALLBACK_SIZE
        default ROM_SECTION_OFFSET = ( ROM_SIZE - FALLBACK_SIZE -
FAILOVER_SIZE )
    else
        default ROM_SECTION_SIZE   = ( ROM_SIZE - FALLBACK_SIZE -
FAILOVER_SIZE )
        default ROM_SECTION_OFFSET = 0
    end
end

##
## Compute the start location and size size of
## The coreboot bootloader.
##
default PAYLOAD_SIZE             = ( ROM_SECTION_SIZE - ROM_IMAGE_SIZE )
default CONFIG_ROM_PAYLOAD_START = (0xffffffff - ROM_SIZE +
ROM_SECTION_OFFSET + 1)

##
## Compute where this copy of coreboot will start in the boot rom
##
default _ROMBASE      = ( CONFIG_ROM_PAYLOAD_START + PAYLOAD_SIZE )

##
## Compute a range of ROM that can cached to speed up coreboot,
## execution speed.
##
## XIP_ROM_SIZE must be a power of 2.
## XIP_ROM_BASE must be a multiple of XIP_ROM_SIZE
##
default XIP_ROM_SIZE=65536
#
if USE_FAILOVER_IMAGE
        default XIP_ROM_BASE = ( _ROMBASE - XIP_ROM_SIZE + ROM_IMAGE_SIZE)
else
    if USE_FALLBACK_IMAGE
        default XIP_ROM_BASE = ( _ROMBASE - XIP_ROM_SIZE +
ROM_IMAGE_SIZE + FAILOVER_SIZE)
    else
        default XIP_ROM_BASE = ( _ROMBASE - XIP_ROM_SIZE + ROM_IMAGE_SIZE)
    end
end
--------------------------------------

I'd like to place the section above in a generic
failover_size_calculation.lb file included by the respective targets.

Regards,
Carl-Daniel