sparc64: Abstract away PIC register accesses.

And, like for the PCR, allow indexing of different PIC register
numbers.

This also removes all of the non-__KERNEL__ bits from asm/perfctr.h,
nothing kernel side should include it any more.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/pcr.h

@@ -2,8 +2,10 @@
 #define __PCR_H
 
 struct pcr_ops {
-	u64 (*read)(unsigned long);
-	void (*write)(unsigned long, u64);
+	u64 (*read_pcr)(unsigned long);
+	void (*write_pcr)(unsigned long, u64);
+	u64 (*read_pic)(unsigned long);
+	void (*write_pic)(unsigned long, u64);
 };
 extern const struct pcr_ops *pcr_ops;