Remove duplicate mips platforms

Author: brson

_data/platforms.yml

@@ -47,7 +47,6 @@ beta:
     - mips-unknown-linux-gnu
     - mipsel-unknown-linux-gnu
     - mips64-unknown-linux-gnuabi64
-    - mips64-unknown-linux-gnuabi64
   -
     - powerpc-unknown-linux-gnu
     - powerpc64-unknown-linux-gnu
@@ -72,7 +71,6 @@ nightly:
     - mips-unknown-linux-gnu
     - mipsel-unknown-linux-gnu
     - mips64-unknown-linux-gnuabi64
-    - mips64-unknown-linux-gnuabi64
   -
     - powerpc-unknown-linux-gnu
     - powerpc64-unknown-linux-gnu