remove mips support and bots

The NDK has deprecated mips and mips64:
https://developer.android.com/ndk/guides/abis.html

Might as well clean this up now while I remember.

Change-Id: Ie4b2334c75208082067cc16fe355d0349c7e0904
Reviewed-on: https://skia-review.googlesource.com/80560
Reviewed-by: Derek Sollenberger <djsollen@google.com>
diff --git a/gn/BUILDCONFIG.gn b/gn/BUILDCONFIG.gn
index 646e277..b81680a 100644
--- a/gn/BUILDCONFIG.gn
+++ b/gn/BUILDCONFIG.gn
@@ -13,7 +13,7 @@
   ndk = ""
 
   # It's nice to keep ndk_api set to what Clank targets, but probably no big deal if we can't.
-  if (target_cpu == "x86" || target_cpu == "mipsel" || target_cpu == "arm") {
+  if (target_cpu == "x86" || target_cpu == "arm") {
     ndk_api = 16
   } else {
     ndk_api = 21
@@ -115,18 +115,6 @@
     ndk_stdlib = "armeabi-v7a"
     ndk_gccdir = ndk_target
     ndk_gdbserver = "prebuilt/android-arm/gdbserver/gdbserver"
-  } else if (target_cpu == "mips64el") {
-    ndk_target = "mips64el-linux-android"
-    ndk_platform = "android-${ndk_api}/arch-mips64"
-    ndk_stdlib = "mips64"
-    ndk_gccdir = ndk_target
-    ndk_gdbserver = "prebuilt/android-mips64/gdbserver/gdbserver"
-  } else if (target_cpu == "mipsel") {
-    ndk_target = "mipsel-linux-android"
-    ndk_platform = "android-${ndk_api}/arch-mips"
-    ndk_stdlib = "mips"
-    ndk_gccdir = ndk_target
-    ndk_gdbserver = "prebuilt/android-mips/gdbserver/gdbserver"
   } else if (target_cpu == "x64") {
     ndk_target = "x86_64-linux-android"
     ndk_platform = "android-${ndk_api}/arch-x86_64"