sh: use the new generic strnlen_user() function

This discards both the _32 and _64 versions in favour of the consolidated
generic one.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index cbffc26..31d9db7 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -33,6 +33,7 @@
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CMOS_UPDATE if SH_SH03 || SH_DREAMCAST
 	select GENERIC_STRNCPY_FROM_USER
+	select GENERIC_STRNLEN_USER
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast