Move platform-dependent files from $prefix to $prefix/$platform.

	Move platform-dependent files from $prefix to $prefix/$platform.

	* config.h.in (GRUB_TARGET_CPU): New definition.
	(GRUB_PLATFORM): Likewise.
	* configure.ac: Define GRUB_TARGET_CPU and GRUB_PLATFORM.
	* grub-core/commands/parttool.c (grub_cmd_parttool): Update dir.
	* grub-core/efiemu/main.c (grub_efiemu_autocore): Likewise.
	* grub-core/kern/dl.c (grub_dl_load): Likewise.
	* grub-core/normal/autofs.c (read_fs_list): Likewise.
	* grub-core/normal/crypto.c (read_crypto_list): Likewise.
	* grub-core/normal/dyncmd.c (read_command_list): Likewise.
	* grub-core/normal/term.c (read_terminal_list): Likewise.
	* grub-core/gettext/gettext.c (grub_mofile_open_lang): Use
	$prefix/locale.
	(grub_gettext_init_ext): Likewise.
	* grub-core/normal/main.c (GRUB_MOD_INIT): Define grub_cpu and
	grub_platform.
	* util/grub-install.in: Update directories.
	* util/grub-mknetdir.in: Likewise.
	* util/grub-mkrescue.in: Likewise.