Fix strace mips64 build.

Change-Id: I2ccae8e2c548c63dd555c420acd1235d109ddcbc
diff --git a/Android.mk b/Android.mk
index c3cb173..320a449 100644
--- a/Android.mk
+++ b/Android.mk
@@ -239,7 +239,7 @@
 LOCAL_CFLAGS_mips += -DMIPS=1 -DLINUX_MIPSO32=1
 LOCAL_CFLAGS_mips += -DHAVE_ASM_SYSMIPS_H=1
 
-LOCAL_CFLAGS_mips64 += -DMIPS=1
+LOCAL_CFLAGS_mips64 += -DMIPS=1 -DLINUX_MIPSN64=1
 LOCAL_CFLAGS_mips64 += -DHAVE_ASM_SYSMIPS_H=1
 
 LOCAL_CFLAGS_x86 += -DI386=1