openrisc: use generic strncpy_from_user

As per commits 2922585b9329 ("lib: Sparc's strncpy_from_user is generic
enough, move under lib/") and 92ae03f2ef99 ("x86: merge 32/64-bit
versions of 'strncpy_from_user()' and speed it up"), and corresponding
discussion on linux-arch.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 4932247..0656232 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -19,6 +19,7 @@
 	select GENERIC_CPU_DEVICES
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS
+	select GENERIC_STRNCPY_FROM_USER
 
 config MMU
 	def_bool y