x86/mips: enable _FORTIFY_SOURCE=2

Enable _FORTIFY_SOURCE=2 for x86 and MIPS.

Currently, this change is a no-op, as Android's libc doesn't
support _FORTIFY_SOURCE > 1, yet.

The ARM change was made in 316f720b91f879c4e3972d6d595535de0ac707b2

Change-Id: Iafe90beadf9b6a41ea294b7107cf4f18141acf3a
diff --git a/core/combo/TARGET_linux-mips.mk b/core/combo/TARGET_linux-mips.mk
index 41928f8..85eaec9 100644
--- a/core/combo/TARGET_linux-mips.mk
+++ b/core/combo/TARGET_linux-mips.mk
@@ -93,7 +93,7 @@
 			-funwind-tables \
 			-Wa,--noexecstack \
 			-Werror=format-security \
-			-D_FORTIFY_SOURCE=1 \
+			-D_FORTIFY_SOURCE=2 \
 			$(arch_variant_cflags)
 
 android_config_h := $(call select-android-config-h,linux-mips)