Fix missing reference in MPU6886 nuspec (#186)

Author: Ellerbach

devices/Mpu6886/Mpu6886.nuspec

@@ -27,6 +27,7 @@
       <dependency id="nanoFramework.System.Math" version="1.4.1" />
       <dependency id="nanoFramework.System.Numerics" version="1.0.160" />
       <dependency id="UnitsNet.nanoFramework.Temperature" version="4.102.0" />
+      <dependency id="nanoFramework.System.Buffers.Binary.BinaryPrimitives" version="1.0.160" />
     </dependencies>
   </metadata>
   <files>