m68k: arch/m68k/kernel/sun3-head.S needs <linux/init.h>

Fix this:

  arch/m68k/kernel/sun3-head.S: Assembler messages:
  arch/m68k/kernel/sun3-head.S:32: Error: Unknown operator -- statement `__head' ignored

Introduced by commit 6f335cab0431d5df4995bcd4fd952d4c746d5a86 ("m68k:
convert to use __HEAD and HEAD_TEXT macros."), which started using
__HEAD without adding the appropriate include.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/m68k/kernel/sun3-head.S b/arch/m68k/kernel/sun3-head.S
index 9e5c3e5..43036bf 100644
--- a/arch/m68k/kernel/sun3-head.S
+++ b/arch/m68k/kernel/sun3-head.S
@@ -1,4 +1,5 @@
 #include <linux/linkage.h>
+#include <linux/init.h>
 
 #include <asm/entry.h>
 #include <asm/page.h>