ARC: Disintegrate arcregs.h

* Move the various sub-system defines/types into relevant files/functions
  (reduces compilation time)

* move CPU specific stuff out of asm/tlb.h into asm/mmu.h

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
index 3357d26..7bf811d 100644
--- a/arch/arc/mm/tlbex.S
+++ b/arch/arc/mm/tlbex.S
@@ -39,7 +39,7 @@
 
 #include <linux/linkage.h>
 #include <asm/entry.h>
-#include <asm/tlb.h>
+#include <asm/mmu.h>
 #include <asm/pgtable.h>
 #include <asm/arcregs.h>
 #include <asm/cache.h>