Revert "Build mips64r6 target with GCC."

This change is no longer needed thanks to
https://android-review.googlesource.com/#/c/204304/.

Bug: 27310199

This reverts commit c9e1a8968c22b86eba444807c9c8bf2898b3b672.

Change-Id: I6915ff18274fef4460dbbf7833b6b2944e0e8fd8
diff --git a/mips64r6/BoardConfig.mk b/mips64r6/BoardConfig.mk
index 9ba2f8c..47eb1d8 100644
--- a/mips64r6/BoardConfig.mk
+++ b/mips64r6/BoardConfig.mk
@@ -27,10 +27,4 @@
 TARGET_SUPPORTS_32_BIT_APPS :=
 TARGET_SUPPORTS_64_BIT_APPS := true
 
-# Build with GCC, as building with Clang exhibit the following build
-# error for dex2oat (b/27310199):
-#
-#   art/dex2oat/dex2oat.cc:2606:5: error: stack frame size of 1808
-#   bytes in function 'main' [-Werror,-Wframe-larger-than=]
-#
-USE_CLANG_PLATFORM_BUILD := false
+USE_CLANG_PLATFORM_BUILD := true