Add msa mips features

References to an MSA architecture feature were added in
I3cadc29434dbd5fdb3aa780198414e90f9572ec5, but never added
to the build system.

Test: builds
Change-Id: I178813824a21475e013f7e8209d9473466ab821c
diff --git a/cc/config/mips_device.go b/cc/config/mips_device.go
index 42025a2..9e27f37 100644
--- a/cc/config/mips_device.go
+++ b/cc/config/mips_device.go
@@ -135,7 +135,8 @@
 		"mips32r6")
 	android.RegisterArchFeatures(android.Mips,
 		"dspr2",
-		"rev6")
+		"rev6",
+		"msa")
 	android.RegisterArchVariantFeatures(android.Mips, "mips32r2dspr2_fp",
 		"dspr2")
 	android.RegisterArchVariantFeatures(android.Mips, "mips32r6",