m68k: Kill several external declarations in source files

- Replace external declarations by proper includes where availiable.
    The accesses to some symbols had to be modified, as before they were
    declared using e.g. "extern int _end", while asm-generic/sections.h uses
    e.g. "extern char _end[]"
  - Remove unused or superfluous external declarations

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/mm/init.c

@@ -28,6 +28,7 @@
 #ifdef CONFIG_ATARI
 #include <asm/atari_stram.h>
 #endif
+#include <asm/sections.h>
 #include <asm/tlb.h>
 
 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
@@ -73,9 +74,6 @@ extern void init_pointer_table(unsigned long ptable);
 
 /* References to section boundaries */
 
-extern char _text[], _etext[];
-extern char __init_begin[], __init_end[];
-
 extern pmd_t *zero_pgtable;
 
 void __init mem_init(void)