Provide the base firmware for the skylake- and avs- drivers to utilize.
This is an updated version of existing intel/dsp_fw_bxtn.bin and
intel/dsp_fw_glk.bin.
Leave links for backward compatibility but put the binaries into a
dedicated folder so it is clear which driver makes use of them.
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>