md/raid6: implement recovery using ARM NEON intrinsics

Provide a NEON accelerated implementation of the recovery algorithm,
which supersedes the default byte-by-byte one.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c
index 7857049..4769947 100644
--- a/lib/raid6/algos.c
+++ b/lib/raid6/algos.c
@@ -113,6 +113,9 @@
 #ifdef CONFIG_S390
 	&raid6_recov_s390xc,
 #endif
+#if defined(CONFIG_KERNEL_MODE_NEON)
+	&raid6_recov_neon,
+#endif
 	&raid6_recov_intx1,
 	NULL
 };