x86, um: now we can get rid of trivial uml headers

arch/um/Makefile

arch/um/include/asm/a.out.h

arch/um/include/asm/alternative-asm.h

arch/um/include/asm/alternative.h

arch/um/include/asm/asm.h

arch/um/include/asm/bitops.h

arch/um/include/asm/boot.h

arch/um/include/asm/bug.h

arch/um/include/asm/byteorder.h

arch/um/include/asm/cacheflush.h

arch/um/include/asm/calling.h

arch/um/include/asm/cmpxchg.h

arch/um/include/asm/cobalt.h

arch/um/include/asm/cpufeature.h

arch/um/include/asm/div64.h

arch/um/include/asm/dwarf2.h

arch/um/include/asm/errno.h

arch/um/include/asm/fcntl.h

arch/um/include/asm/floppy.h

arch/um/include/asm/frame.h