mpc85xx: tlb.c cleanups

Extract the operation to read a tlb into a function - we will need
this later to print out the tlbs, and there's no point in duplicating
the code.  Create a TSIZE_TO_BYTES macro to deal with the conversion
from the MAS field to an actual size instead of duplicating this in code.
There are a few misc other minor cleanups.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 5166507..d4c7b75 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -402,6 +402,7 @@
 #define MAS1_TID(x)	((x << 16) & 0x3FFF0000)
 #define MAS1_TS		0x00001000
 #define MAS1_TSIZE(x)	((x << 8) & 0x00000F00)
+#define TSIZE_TO_BYTES(x) ((phys_addr_t)(1UL << ((tsize * 2) + 10)))
 
 #define MAS2_EPN	0xFFFFF000
 #define MAS2_X0		0x00000040