[MIPS] TX49XX has prefetch.
    
The TX49XX has the prefetch instruction.  It supports only Pref_Load
(hint 0).  Actually changes in this patch except for Kconfig are not
have any effects, I added these changes to prevent misuse of unsupported
hints.
    
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 97a9769..ac2012f 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1160,6 +1160,7 @@
 config CPU_TX49XX
 	bool "R49XX"
 	depends on SYS_HAS_CPU_TX49XX
+	select CPU_HAS_PREFETCH
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL