wireguard: upgrade to 0.0.20180910

[zx2c4]

  * curve25519: arm: do not modify sp directly
  * compat: support neon.h on old kernels
  * compat: arch-namespace certain includes
  * compat: move simd.h from crypto to compat since it's going upstream

  This fixes a decent amount of compat breakage and thumb2-mode breakage
  introduced by our move to Zinc.

  * crypto: use CRYPTOGAMS license

  Rather than using code from OpenSSL, use code directly from AndyP.

  * poly1305: rewrite self tests from scratch
  * poly1305: switch to donna

  This makes our C Poly1305 implementation a bit more intensely tested and also
  faster, especially on 64-bit systems. It also sets the stage for moving to a
  HACL* implementation when that's ready.

[rn]

Thanks for the update. We'll pick this up as usual with the next kernel updates