x86: Import code from coreboot's libpayload to parse the coreboot table

x86: Import code from coreboot's libpayload to parse the coreboot table

This change also forces the lib_sysinfo structure to be in the .data
section. Otherwise it ends up in the .bss section. U-boot assumes that it
doesn't need to copy it over during relocation, and instead fills that
whole section with zeroes. If we really were booting from ROM that would be
appropriate, but we need some information from the coreboot tables (memory
size) before then and have to fill that structure before relocation. We
skirt u-boot's assumption by putting this in .data where it assumes there
is still read only but non-zero data.

Signed-off-by: Gabe Black <gabeblack@chromium.org>