powerpc: Remove power3 from comments

There are still a few occurences where it remains, because it helps to
explain something that persists.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index 11571e1..5029dc1 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -2,7 +2,7 @@
  * This file contains the routines for handling the MMU on those
  * PowerPC implementations where the MMU substantially follows the
  * architecture specification.  This includes the 6xx, 7xx, 7xxx,
- * 8260, and POWER3 implementations but excludes the 8xx and 4xx.
+ * and 8260 implementations but excludes the 8xx and 4xx.
  *  -- paulus
  *
  *  Derived from arch/ppc/mm/init.c: