coreboot_tables: Replace 'struct lb_uint64' with lb_uint64_t

Replace 'struct lb_uint64' with 'typedef __aligned(4) uint64_t
lb_uint64_t', and remove unpack_lb64/pack_lb64 functions since it's no
longer needed.

Also replace 'struct cbuint64' with 'cb_uint64_t' and remove
'cb_unpack64' in libpayload for compatible with lb_uint64_t.

Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Change-Id: If6b037e4403a8000625f4a5fb8d20311fe76200a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63494
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

util/cbmem/cbmem.c

@@ -1016,7 +1016,7 @@ static void dump_cbmem_hex(void)
 		return;
 	}
 
-	hexdump(unpack_lb64(cbmem.start), unpack_lb64(cbmem.size));
+	hexdump(cbmem.start, cbmem.size);
 }
 
 static void rawdump(uint64_t base, uint64_t size)