powerpc: Add macros to access floating point registers in thread_struct.

We are going to change where the floating point registers are stored
in the thread_struct, so in preparation add some macros to access the
floating point registers.  Update all code to use these new macros.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/processor.h b/include/asm-powerpc/processor.h
index a1deed8..a23da63 100644
--- a/include/asm-powerpc/processor.h
+++ b/include/asm-powerpc/processor.h
@@ -12,6 +12,8 @@
 
 #include <asm/reg.h>
 
+#define TS_FPRWIDTH 1
+
 #ifndef __ASSEMBLY__
 #include <linux/compiler.h>
 #include <asm/ptrace.h>
@@ -140,6 +142,8 @@
 	unsigned long seg;
 } mm_segment_t;
 
+#define TS_FPR(i) fpr[i]
+
 struct thread_struct {
 	unsigned long	ksp;		/* Kernel stack pointer */
 	unsigned long	ksp_limit;	/* if ksp <= ksp_limit stack overflow */