libata: Implement ATA_FLAG_NO_DIPM and apply it to mcp65

NVIDIA mcp65 familiy of controllers cause command timeouts when DIPM
is used.  Implement ATA_FLAG_NO_DIPM and apply it.

This problem was reported by Stefan Bader in the following thread.

 http://thread.gmane.org/gmane.linux.ide/48841

stable: applicable to 2.6.37 and 38.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 3b4d223..04f32a3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -196,6 +196,7 @@
 					      * management */
 	ATA_FLAG_SW_ACTIVITY	= (1 << 22), /* driver supports sw activity
 					      * led */
+	ATA_FLAG_NO_DIPM	= (1 << 23), /* host not happy with DIPM */
 
 	/* bits 24:31 of ap->flags are reserved for LLD specific flags */