* include/multiboot2.h (multiboot_word): Rename from this ...
(multiboot2_word): ... to this. Update all users.
(multiboot_header): Rename from this ...
(multiboot2_header): ... to this. Update all users.
(multiboot_tag_header): Rename from this ...
(multiboot2_tag_header): ... to this. Update all users.
(multiboot_tag_start): Rename from this ...
(multiboot2_tag_start): ... to this. Update all users.
(multiboot_tag_name): Rename from this ...
(multiboot2_tag_name): ... to this. Update all users.
(multiboot_tag_module): Rename from this ...
(multiboot2_tag_module): ... to this. Update all users.
(multiboot_tag_memory): Rename from this ...
(multiboot2_tag_memory): ... to this. Update all users.
(multiboot_tag_unused): Rename from this ...
(multiboot2_tag_unused): ... to this. Update all users.
(multiboot_tag_end): Rename from this ...
(multiboot2_tag_end): ... to this. Update all users.