AMD Fam15tn: Add support for AGESA runtime allocation in CBMEM

The IOMMU AGESA needs a reserved scratch space and it wants
to allocate the stuff for runtime. So provide a simple
allocator for 4 KB CBMEM page.

Change-Id: I53bdfcd2cd69f84fbfbc6edea53a051f516c05cc
Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Reviewed-on: http://review.coreboot.org/3315
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/lib/cbmem_info.c

@@ -47,6 +47,7 @@ static struct cbmem_id_to_name {
 	{ CBMEM_ID_ROOT,		"CBMEM ROOT " },
 	{ CBMEM_ID_VBOOT_HANDOFF,	"VBOOT      " },
 	{ CBMEM_ID_CAR_GLOBALS,		"CAR GLOBALS" },
+	{ CBMEM_ID_AGESA_RUNTIME,	"AGESA RSVD " },
 };
 
 void cbmem_print_entry(int n, u32 id, u64 base, u64 size)