coreboot: introduce notion of bootmem for memory map at boot

The write_coreboot_table() in coreboot_table.c was already using
struct memrange for managing and building up the entries that
eventually go into the lb_memory table. Abstract that concept
out to a bootmem memory map. The bootmem concept can then be
used as a basis for loading payloads, for example.

Change-Id: I7edbbca6bbd0568f658fde39ca93b126cab88367
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/5302
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

src/include/boot/coreboot_tables.h

@@ -338,9 +338,6 @@ unsigned long write_coreboot_table(
 	unsigned long low_table_start, unsigned long low_table_end,
 	unsigned long rom_table_start, unsigned long rom_table_end);
 
-void lb_add_memory_range(struct lb_memory *mem,
-	uint32_t type, uint64_t start, uint64_t size);
-
 /* Routines to extract part so the coreboot table or information
  * from the coreboot table.
  */