fw_sst_0f28: Add firmware for Intel Baytrail SST DSP

Add firmware file and licence for Intel Baytrail SST DSP audio.
The firmware is distributed under Intel Free Redistribution License.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mengdong Lin <mengdong.lin@intel.com>
Signed-off-by: Kyle McMartin <kyle@kernel.org>

LICENCE.fw_sst_0f28

+Copyright (c) 2014 Intel Corporation.
+All rights reserved.
+
+Redistribution.
+
+Redistribution and use in binary form, without modification, are permitted
+provided that the following conditions are met:
+*    Redistributions must reproduce the above copyright notice and the
+     following disclaimer in the documentation and/or other materials provided
+     with the distribution.
+*    Neither the name of Intel Corporation nor the names of its suppliers may
+     be used to endorse or promote products derived from this software without
+     specific prior written permission.
+*    No reverse engineering, decompilation, or disassembly of this software is
+     permitted.
+
+
+Limited patent license.
+
+Intel Corporation grants a world-wide, royalty-free, non-exclusive license
+under patents it now or hereafter owns or controls to make, have made, use,
+import, offer to sell and sell ("Utilize") this software, but solely to the
+extent that any such patent is necessary to Utilize the software alone. The
+patent license shall not apply to any combinations which include this software.
+No hardware per se is licensed hereunder.
+
+
+DISCLAIMER.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+--------------------------------------------------------------------------
+
+Driver: snd_soc_sst_acpi
+
+File: intel/fw_sst_0f28.bin-48kHz_i2s_master
+
+License: Redistributable. See LICENCE.fw_sst_0f28 for details
+
+--------------------------------------------------------------------------