powerpc/fsl-booke: Don't hard-code size of struct tlbcam

Some assembly code in head_fsl_booke.S hard-coded the size of struct tlbcam
to 20 when it indexed the TLBCAM table.  Anyone changing the size of struct
tlbcam would not know to expect that.

The kernel already has a system to get the size of C structures into
assembly language files, asm-offsets, so let's use it.

The definition of the struct gets moved to a header, so that asm-offsets.c
can include it.

Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/mm/fsl_booke_mmu.c

@@ -61,13 +61,7 @@ static unsigned long __cam0, __cam1, __cam2;
 
 #define NUM_TLBCAMS	(16)
 
-struct tlbcam {
-   	u32	MAS0;
-	u32	MAS1;
-	u32	MAS2;
-	u32	MAS3;
-	u32	MAS7;
-} TLBCAM[NUM_TLBCAMS];
+struct tlbcam TLBCAM[NUM_TLBCAMS];
 
 struct tlbcamrange {
    	unsigned long start;