h8300: Fix <asm/tlb.h>

Ten years ago, a mismerge happened, concatenating two slightly different
versions of the same file. As a consequence, <asm-generic/tlb.h> was never
included, leading to a build failure only now:

kernel/cpu/idle.c: In function 'cpu_idle_loop':
kernel/cpu/idle.c:70:4: error: implicit declaration of function 'check_pgt_cache' [-Werror=implicit-function-declaration]

Remove the duplicates, and the header comment with the no longer correct
file name.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>

arch/h8300/include/asm/tlb.h

-/* 
-  include/asm-h8300/tlb.h 
-*/
-
-#ifndef __H8300_TLB_H__
-#define __H8300_TLB_H__
-
-#define tlb_flush(tlb)	do { } while(0)
-
-/* 
-  include/asm-h8300/tlb.h 
-*/
-
 #ifndef __H8300_TLB_H__
 #define __H8300_TLB_H__
 
@@ -19,5 +6,3 @@
 #include <asm-generic/tlb.h>
 
 #endif
-
-#endif