linux-firmware: Add firmware for Ralink drivers

Add the firmware files for use with rt61pci, rt73usb, rt2860sta and
rt2870sta drivers.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

LICENSE.ralink-firmware.txt

+Copyright (c) 2007, Ralink Technology 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 Ralink Technology 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. Ralink Technology 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, or in 
+combination with an operating system licensed under an approved Open 
+Source license as listed by the Open Source Initiative at 
+http://opensource.org/licenses.  The patent license shall not apply to 
+any other 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.

WHENCE

@@ -797,3 +797,43 @@ Licence: Unknown
 
 Found in hex form in kernel source.
 
+--------------------------------------------------------------------------
+
+Driver: rt61pci - Ralink RT2561, RT2561S, RT2661 wireless MACs
+
+File: rt2561.bin rt2561s.bin rt2661.bin
+
+Licence: Redistributable. See LICENSE.ralink-firmware.txt for details
+
+Downloaded from http://www.ralinktech.com/ralink/Home/Support/Linux.html
+
+--------------------------------------------------------------------------
+
+Driver: rt73usb - Ralink RT2571W, RT2671 wireless MACs
+
+File: rt73.bin
+
+Licence: Redistributable. See LICENSE.ralink-firmware.txt for details
+
+Downloaded from http://www.ralinktech.com/ralink/Home/Support/Linux.html
+
+--------------------------------------------------------------------------
+
+Driver: rt2860sta - Ralink RT2860, RT2890 wireless MACs
+
+File: rt2860.bin
+
+Licence: Redistributable. See LICENSE.ralink-firmware.txt for details
+
+Downloaded from http://www.ralinktech.com/ralink/Home/Support/Linux.html
+
+--------------------------------------------------------------------------
+
+Driver: rt2870sta - Ralink RT2870 wireless MACs
+
+File: rt2870.bin
+
+Licence: Redistributable. See LICENSE.ralink-firmware.txt for details
+
+Downloaded from http://www.ralinktech.com/ralink/Home/Support/Linux.html
+