x86: Rename i386 to x86

arch/x86/include/asm/bootparam.h

arch/x86/include/asm/byteorder.h

arch/x86/include/asm/config.h

arch/x86/include/asm/e820.h

arch/x86/include/asm/errno.h

arch/x86/include/asm/global_data.h

arch/x86/include/asm/i8254.h

arch/x86/include/asm/i8259.h

arch/x86/include/asm/ibmpc.h

arch/x86/include/asm/ic/pci.h

arch/x86/include/asm/ic/sc520.h

arch/x86/include/asm/ic/ssi.h

arch/x86/include/asm/interrupt.h

arch/x86/include/asm/io.h

arch/x86/include/asm/ioctl.h

arch/x86/include/asm/ist.h

arch/x86/include/asm/pci.h

arch/x86/include/asm/posix_types.h

arch/x86/include/asm/processor-flags.h

arch/x86/include/asm/processor.h