Clean up interface

src/kernel/include/multiboot.h

@@ -7,19 +7,6 @@ struct kernel_boot_data_st
   char *commandline;
 };
 
-struct kernel_boot_data_st kernel_boot_data;
-
-struct mboot2_taglist{
-  uint32_t total_size;
-  uint32_t reserved;
-}__attribute__((packed));
-struct mboot2_tag {
-  uint32_t type;
-  uint32_t size;
-  uint8_t data[];
-}__attribute__((packed));
-
-#define MBOOT2_COMMANDLINE 1
-#define MBOOT2_BOOTLOADER 2
+extern struct kernel_boot_data_st kernel_boot_data;
 
 int multiboot_init(uint64_t magic, void *mboot_info);