Remove -march=native from build flags.

--- a/higan/GNUmakefile
+++ b/higan/GNUmakefile
@@ -32,7 +32,7 @@ ifeq ($(platform),windows)
 else ifeq ($(platform),macosx)
   flags += -march=native
 else ifneq ($(filter $(platform),linux bsd),)
-  flags += -march=native -fopenmp
+  flags += -fopenmp
   link += -fopenmp
   link += -Wl,-export-dynamic
   link += -lX11 -lXext
