mips: Use common _AC macro now.

MIPS no longer needs to have its own version of this macro now.

Fixes: 2a6713b09b ("move UL() macro from armv8/mmu.h into common.h")
Signed-off-by: Tom Rini <trini@konsulko.com>

arch/mips/include/asm/const.h

@@ -17,11 +17,8 @@
  */
 
 #ifdef __ASSEMBLY__
-#define _AC(X,Y)	X
 #define _AT(T,X)	X
 #else
-#define __AC(X,Y)	(X##Y)
-#define _AC(X,Y)	__AC(X,Y)
 #define _AT(T,X)	((T)(X))
 #endif