x86: Rename i386 to x86

arch/x86/include/asm/ptrace.h

arch/x86/include/asm/realmode.h

arch/x86/include/asm/string.h

arch/x86/include/asm/types.h

arch/x86/include/asm/u-boot-x86.h

arch/x86/include/asm/u-boot.h

arch/x86/include/asm/unaligned.h

arch/x86/include/asm/video/edid.h

arch/x86/include/asm/zimage.h

arch/x86/lib/Makefile

arch/x86/lib/bios.S

arch/x86/lib/bios.h

arch/x86/lib/bios_pci.S

arch/x86/lib/bios_setup.c

arch/x86/lib/board.c

arch/x86/lib/bootm.c

arch/x86/lib/interrupts.c

arch/x86/lib/pcat_interrupts.c

arch/x86/lib/pcat_timer.c

arch/x86/lib/pci.c