Tweak default x86 target arch variant.

Simply set the arch variant for sim-eng to be "x86".
diff --git a/core/combo/TARGET_linux-x86.mk b/core/combo/TARGET_linux-x86.mk
index ddd5c48..b8f770f 100644
--- a/core/combo/TARGET_linux-x86.mk
+++ b/core/combo/TARGET_linux-x86.mk
@@ -25,6 +25,7 @@
 TARGET_GLOBAL_CFLAGS := $(HOST_GLOBAL_CFLAGS) -m32
 TARGET_GLOBAL_LDFLAGS := $(HOST_GLOBAL_LDFLAGS) -m32
 TARGET_NO_UNDEFINED_LDFLAGS := $(HOST_NO_UNDEFINED_LDFLAGS)
+TARGET_ARCH_VARIANT := x86
 else #simulator
 
 # Provide a default variant.