Create/use more directory structure in the Documentation/ tree.

Create Documentation/blockdev/ sub-directory and populate it.
Populate the Documentation/serial/ sub-directory.
Move MSI-HOWTO.txt to Documentation/PCI/.
Move ioctl-number.txt to Documentation/ioctl/.
Update all relevant 00-INDEX files.
Update all relevant Kconfig files and source files.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
diff --git a/Documentation/PCI/00-INDEX b/Documentation/PCI/00-INDEX
index 49f4394..812b17f 100644
--- a/Documentation/PCI/00-INDEX
+++ b/Documentation/PCI/00-INDEX
@@ -1,5 +1,7 @@
 00-INDEX
 	- this file
+MSI-HOWTO.txt
+	- the Message Signaled Interrupts (MSI) Driver Guide HOWTO and FAQ.
 PCI-DMA-mapping.txt
 	- info for PCI drivers using DMA portably across all platforms
 PCIEBUS-HOWTO.txt