chromeos: provide option to dynamically allocate ram oops buffer

Fixing the location of the ram oops buffer can lead to certain
kernel and boot loaders being confused when there is a ram
reservation low in the address space. Alternatively provide
a mechanism to allocate the ram oops buffer in cbmem. As cbmem
is usually high in the address space it avoids low reservation
confusion.

The patch uncondtionally provides a GOOG9999 ACPI device with
a single memory resource describing the memory region used for
the ramoops region.

BUG=None
BRANCH=baytrail,haswell
TEST=Built and booted with and w/o dynamic ram oops. With
     the corresponding kernel change things behave correctly.

Change-Id: Ide2bb4434768c9f9b90e125adae4324cb1d2d073
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/5257
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/lib/cbmem_info.c

@@ -52,6 +52,7 @@ static struct cbmem_id_to_name {
 	{ CBMEM_ID_REFCODE,		"REFCODE    " },
 	{ CBMEM_ID_SMM_SAVE_SPACE,	"SMM BACKUP " },
 	{ CBMEM_ID_REFCODE_CACHE,	"REFCODE $  " },
+	{ CBMEM_ID_RAM_OOPS,		"RAMOOPS    " },
 };
 
 void cbmem_print_entry(int n, u32 id, u64 base, u64 size)