MIPS: Remove duplicated include in local.h

Fix following includecheck warning:
./arch/mips/include/asm/local.h: asm/asm.h is included more than once.

Reported-by: Abaci Robot <[e-mail]>
Signed-off-by: Yang Li <[e-mail]>
Signed-off-by: Thomas Bogendoerfer <[e-mail]>

arch/mips/include/asm/local.h

···
 #include <asm/asm.h>
 #include <asm/cmpxchg.h>
 #include <asm/compiler.h>
-#include <asm/asm.h>
 
 typedef struct
 {