byteorder: Add le64_to_cpu_array() and cpu_to_le64_array()

Add le64_to_cpu_array() and cpu_to_le64_array(). These mirror the
corresponding 32-bit functions.

These will be used by the BLAKE2b code.

Reviewed-by: Ard Biesheuvel <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Eric Biggers <[e-mail]>

include/linux/byteorder/generic.h

···
 	}
 }
 
+static inline void le64_to_cpu_array(u64 *buf, unsigned int words)
+{
+	while (words--) {
+		__le64_to_cpus(buf);
+		buf++;
+	}
+}
+
+static inline void cpu_to_le64_array(u64 *buf, unsigned int words)
+{
+	while (words--) {
+		__cpu_to_le64s(buf);
+		buf++;
+	}
+}
+
 static inline void memcpy_from_le32(u32 *dst, const __le32 *src, size_t words)
 {
 	size_t i;