dm: add vSBL binary in bios directory

Create a new diectory bios in devicemodel
Add vSBL binary in bios directory.
- VSBL.bin: release version of vSBL
- VSBL_debug.bin: debug version of vSBL

Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Reviewed-by: Jack Ren <jack.ren@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: binbinwu1